[INFO] updating cached repository https://github.com/evgeni-nabokov/leetcode-rust
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] [stderr] From https://github.com/evgeni-nabokov/leetcode-rust
[INFO] [stderr]    3a4a8fb..57f5322  master     -> master
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 57f53228286e0205dcec592856d038ff6e38c85e
[INFO] checking evgeni-nabokov/leetcode-rust against master#bd0bacc694d7d8175804bb6f690cb846bfa4a9ee for pr-71665
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fevgeni-nabokov%2Fleetcode-rust" "/workspace/builds/worker-0/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/evgeni-nabokov/leetcode-rust on toolchain bd0bacc694d7d8175804bb6f690cb846bfa4a9ee
[INFO] running `"/workspace/cargo-home/bin/cargo" "+bd0bacc694d7d8175804bb6f690cb846bfa4a9ee" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/evgeni-nabokov/leetcode-rust
[INFO] finished tweaking git repo https://github.com/evgeni-nabokov/leetcode-rust
[INFO] tweaked toml for git repo https://github.com/evgeni-nabokov/leetcode-rust written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/evgeni-nabokov/leetcode-rust already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+bd0bacc694d7d8175804bb6f690cb846bfa4a9ee" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+bd0bacc694d7d8175804bb6f690cb846bfa4a9ee" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 0c69f4905b1da216140d8fba7d02bbf80982e830d2c842802ea2e9ed1f3423fe
[INFO] running `"docker" "start" "-a" "0c69f4905b1da216140d8fba7d02bbf80982e830d2c842802ea2e9ed1f3423fe"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]     Checking leetcode v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `crate::challenge_2020_04::tree_node::TreeNode`
[INFO] [stderr]   --> src/challenge_2020_04/mod.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 | use crate::challenge_2020_04::tree_node::TreeNode;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `min`
[INFO] [stderr]  --> src/challenge_2020_05/mod.rs:6:21
[INFO] [stderr]   |
[INFO] [stderr] 6 | use std::cmp::{max, min};
[INFO] [stderr]   |                     ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `HashMap`
[INFO] [stderr]  --> src/contest_187/mod.rs:1:33
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::collections::{HashSet, HashMap};
[INFO] [stderr]   |                                 ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `max`, `min`
[INFO] [stderr]  --> src/contest_187/mod.rs:2:16
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::cmp::{min, max};
[INFO] [stderr]   |                ^^^  ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]  --> src/common/tree_node_tests.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use super::*;
[INFO] [stderr]   |     ^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `crate::challenge_2020_04::tree_node::TreeNode`
[INFO] [stderr]   --> src/challenge_2020_04/mod.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 | use crate::challenge_2020_04::tree_node::TreeNode;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `min`
[INFO] [stderr]  --> src/challenge_2020_05/mod.rs:6:21
[INFO] [stderr]   |
[INFO] [stderr] 6 | use std::cmp::{max, min};
[INFO] [stderr]   |                     ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `HashMap`
[INFO] [stderr]  --> src/contest_187/mod.rs:1:33
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::collections::{HashSet, HashMap};
[INFO] [stderr]   |                                 ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `max`, `min`
[INFO] [stderr]  --> src/contest_187/mod.rs:2:16
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::cmp::{min, max};
[INFO] [stderr]   |                ^^^  ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stderr]  --> src/common/tree_node.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::borrow::BorrowMut;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/contest_184/mod.rs:92:12
[INFO] [stderr]    |
[INFO] [stderr] 92 |        for i in 2..=n {
[INFO] [stderr]    |            ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:103:33
[INFO] [stderr]     |
[INFO] [stderr] 103 |                 Entry::Occupied(mut o) if *o.get() >= nums.len() / 2 => {
[INFO] [stderr]     |                                 ----^
[INFO] [stderr]     |                                 |
[INFO] [stderr]     |                                 help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:109:31
[INFO] [stderr]     |
[INFO] [stderr] 109 |                 Entry::Vacant(mut v) => {
[INFO] [stderr]     |                               ----^
[INFO] [stderr]     |                               |
[INFO] [stderr]     |                               help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `create_from_level_order`
[INFO] [stderr]   --> src/common/tree_node.rs:14:5
[INFO] [stderr]    |
[INFO] [stderr] 14 |     pub fn create_from_level_order(values: &[Option<i32>]) -> Option<Rc<RefCell<TreeNode>>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `insert_level_order`
[INFO] [stderr]   --> src/common/tree_node.rs:15:12
[INFO] [stderr]    |
[INFO] [stderr] 15 |         fn insert_level_order(values: &[Option<i32>], i: usize) -> Option<Rc<RefCell<TreeNode>>> {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `new_with_children`
[INFO] [stderr]   --> src/common/tree_node.rs:42:5
[INFO] [stderr]    |
[INFO] [stderr] 42 | /     pub fn new_with_children(val: i32, left: Option<Rc<RefCell<TreeNode>>>, right: Option<Rc<RefCell<TreeNode>>>)
[INFO] [stderr] 43 | |                   -> Option<Rc<RefCell<TreeNode>>> {
[INFO] [stderr] 44 | |         Some(Rc::new(RefCell::new(TreeNode {
[INFO] [stderr] 45 | |             val,
[INFO] [stderr] ...  |
[INFO] [stderr] 48 | |         })))
[INFO] [stderr] 49 | |     }
[INFO] [stderr]    | |_____^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `new`
[INFO] [stderr]   --> src/challenge_2020_04/list_node.rs:10:5
[INFO] [stderr]    |
[INFO] [stderr] 10 |     pub fn new(val: i32) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `new`
[INFO] [stderr]   --> src/challenge_2020_04/tree_node.rs:14:5
[INFO] [stderr]    |
[INFO] [stderr] 14 |     pub fn new(val: i32) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `MinStack`
[INFO] [stderr]  --> src/challenge_2020_04/min_stack.rs:3:12
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub struct MinStack {
[INFO] [stderr]   |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `new`
[INFO] [stderr]  --> src/challenge_2020_04/min_stack.rs:8:5
[INFO] [stderr]   |
[INFO] [stderr] 8 |     pub fn new() -> Self {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `push`
[INFO] [stderr]   --> src/challenge_2020_04/min_stack.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 12 |     pub fn push(&mut self, x: i32) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `pop`
[INFO] [stderr]   --> src/challenge_2020_04/min_stack.rs:16:5
[INFO] [stderr]    |
[INFO] [stderr] 16 |     pub fn pop(&mut self) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `top`
[INFO] [stderr]   --> src/challenge_2020_04/min_stack.rs:20:5
[INFO] [stderr]    |
[INFO] [stderr] 20 |     pub fn top(&mut self) -> Option<i32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `get_min`
[INFO] [stderr]   --> src/challenge_2020_04/min_stack.rs:28:5
[INFO] [stderr]    |
[INFO] [stderr] 28 |     pub fn get_min(&self) -> Option<i32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `apply_backspaces`
[INFO] [stderr]   --> src/challenge_2020_04/mod.rs:16:8
[INFO] [stderr]    |
[INFO] [stderr] 16 | pub fn apply_backspaces(iter: &mut Rev<Chars>) -> Option<char> {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]   --> src/challenge_2020_04/mod.rs:29:8
[INFO] [stderr]    |
[INFO] [stderr] 29 | struct Solution;
[INFO] [stderr]    |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `single_number`
[INFO] [stderr]   --> src/challenge_2020_04/mod.rs:33:5
[INFO] [stderr]    |
[INFO] [stderr] 33 |     pub fn single_number(mut nums: Vec<i32>) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `single_number_v2`
[INFO] [stderr]   --> src/challenge_2020_04/mod.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     pub fn single_number_v2(nums: Vec<i32>) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `is_happy`
[INFO] [stderr]   --> src/challenge_2020_04/mod.rs:62:5
[INFO] [stderr]    |
[INFO] [stderr] 62 |     pub fn is_happy(n: i32) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `max_sub_array`
[INFO] [stderr]   --> src/challenge_2020_04/mod.rs:88:5
[INFO] [stderr]    |
[INFO] [stderr] 88 |     pub fn max_sub_array(nums: Vec<i32>) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `max_sub_array_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:112:5
[INFO] [stderr]     |
[INFO] [stderr] 112 |     pub fn max_sub_array_v2(nums: Vec<i32>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `move_zeroes`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:124:5
[INFO] [stderr]     |
[INFO] [stderr] 124 |     pub fn move_zeroes(nums: &mut Vec<i32>) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `move_zeroes_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:142:5
[INFO] [stderr]     |
[INFO] [stderr] 142 |     pub fn move_zeroes_v2(nums: &mut Vec<i32>) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `max_profit`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:159:5
[INFO] [stderr]     |
[INFO] [stderr] 159 |     pub fn max_profit(prices: Vec<i32>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `max_profit_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:196:5
[INFO] [stderr]     |
[INFO] [stderr] 196 |     pub fn max_profit_v2(prices: Vec<i32>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `group_anagrams`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:211:5
[INFO] [stderr]     |
[INFO] [stderr] 211 |     pub fn group_anagrams(strs: Vec<String>) -> Vec<Vec<String>> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `group_anagrams_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:230:5
[INFO] [stderr]     |
[INFO] [stderr] 230 |     pub fn group_anagrams_v2(strs: Vec<String>) -> Vec<Vec<String>> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `count_elements`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:247:5
[INFO] [stderr]     |
[INFO] [stderr] 247 |     pub fn count_elements(mut arr: Vec<i32>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `middle_node`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:267:5
[INFO] [stderr]     |
[INFO] [stderr] 267 |     pub fn middle_node(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `backspace_compare`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:284:5
[INFO] [stderr]     |
[INFO] [stderr] 284 |     pub fn backspace_compare(s: String, t: String) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `last_stone_weight`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:297:5
[INFO] [stderr]     |
[INFO] [stderr] 297 |     pub fn last_stone_weight(stones: Vec<i32>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `find_max_length`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:315:5
[INFO] [stderr]     |
[INFO] [stderr] 315 |     pub fn find_max_length(nums: Vec<i32>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `find_max_length_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:332:5
[INFO] [stderr]     |
[INFO] [stderr] 332 |     pub fn find_max_length_v2(nums: Vec<i32>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `string_shift`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:352:5
[INFO] [stderr]     |
[INFO] [stderr] 352 |     pub fn string_shift(s: String, shift: Vec<Vec<i32>>) -> String {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `product_except_self`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:369:5
[INFO] [stderr]     |
[INFO] [stderr] 369 |     pub fn product_except_self(nums: Vec<i32>) -> Vec<i32> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `product_except_self_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:384:5
[INFO] [stderr]     |
[INFO] [stderr] 384 |     pub fn product_except_self_v2(nums: Vec<i32>) -> Vec<i32> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `check_valid_string`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:400:5
[INFO] [stderr]     |
[INFO] [stderr] 400 |     pub fn check_valid_string(s: String) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `num_islands`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:425:5
[INFO] [stderr]     |
[INFO] [stderr] 425 |     pub fn num_islands(grid: Vec<Vec<char>>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `visit_cell`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:431:12
[INFO] [stderr]     |
[INFO] [stderr] 431 |         fn visit_cell((x, y): (i32, i32), &(w, h): &(i32, i32), grid: &Vec<Vec<char>>, mut visited_cells: HashSet<i32>) -> HashSet<i32> {
[INFO] [stderr]     |            ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `num_islands_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:465:5
[INFO] [stderr]     |
[INFO] [stderr] 465 |     pub fn num_islands_v2(mut grid: Vec<Vec<char>>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `visit_cell`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:470:12
[INFO] [stderr]     |
[INFO] [stderr] 470 |         fn visit_cell((x, y): (i32, i32), &(w, h): &(i32, i32), grid: &mut Vec<Vec<char>>) {
[INFO] [stderr]     |            ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `min_path_sum`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:492:5
[INFO] [stderr]     |
[INFO] [stderr] 492 |     pub fn min_path_sum(grid: Vec<Vec<i32>>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `search`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:511:5
[INFO] [stderr]     |
[INFO] [stderr] 511 |     pub fn search(nums: Vec<i32>, target: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `subarray_sum`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:541:5
[INFO] [stderr]     |
[INFO] [stderr] 541 |     pub fn subarray_sum(nums: Vec<i32>, k: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `subarray_sum_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:560:5
[INFO] [stderr]     |
[INFO] [stderr] 560 |     pub fn subarray_sum_v2(nums: Vec<i32>, k: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `subarray_sum_v3`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:579:5
[INFO] [stderr]     |
[INFO] [stderr] 579 |     pub fn subarray_sum_v3(nums: Vec<i32>, k: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `subarray_sum_v4`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:594:5
[INFO] [stderr]     |
[INFO] [stderr] 594 |     pub fn subarray_sum_v4(nums: Vec<i32>, k: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `range_bitwise_and`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:609:5
[INFO] [stderr]     |
[INFO] [stderr] 609 |     pub fn range_bitwise_and(mut m: i32, mut n: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `can_jump`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:619:5
[INFO] [stderr]     |
[INFO] [stderr] 619 |     pub fn can_jump(nums: Vec<i32>) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `can_jump_recursive`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:624:5
[INFO] [stderr]     |
[INFO] [stderr] 624 |     fn can_jump_recursive(nums: &[i32]) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `can_jump_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:637:5
[INFO] [stderr]     |
[INFO] [stderr] 637 |     pub fn can_jump_v2(nums: Vec<i32>) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `longest_common_subsequence`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:650:5
[INFO] [stderr]     |
[INFO] [stderr] 650 |     pub fn longest_common_subsequence(text_1: String, text_2: String) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `maximal_square`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:669:5
[INFO] [stderr]     |
[INFO] [stderr] 669 |     pub fn maximal_square(matrix: Vec<Vec<char>>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `maximal_square_v2`
[INFO] [stderr]    --> src/challenge_2020_04/mod.rs:688:5
[INFO] [stderr]     |
[INFO] [stderr] 688 |     pub fn maximal_square_v2(matrix: Vec<Vec<char>>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/challenge_2020_05/mod.rs:8:12
[INFO] [stderr]   |
[INFO] [stderr] 8 | pub struct Solution;
[INFO] [stderr]   |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `num_jewels_in_stones`
[INFO] [stderr]   --> src/challenge_2020_05/mod.rs:11:5
[INFO] [stderr]    |
[INFO] [stderr] 11 |     pub fn num_jewels_in_stones(jewels: String, stones: String) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `can_construct`
[INFO] [stderr]   --> src/challenge_2020_05/mod.rs:26:5
[INFO] [stderr]    |
[INFO] [stderr] 26 |     pub fn can_construct(ransom_note: String, magazine: String) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `can_construct_v2`
[INFO] [stderr]   --> src/challenge_2020_05/mod.rs:46:5
[INFO] [stderr]    |
[INFO] [stderr] 46 |     pub fn can_construct_v2(ransom_note: String, magazine: String) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `bitwise_complement`
[INFO] [stderr]   --> src/challenge_2020_05/mod.rs:63:5
[INFO] [stderr]    |
[INFO] [stderr] 63 |     pub fn bitwise_complement(n: i32) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `bitwise_complement_v2`
[INFO] [stderr]   --> src/challenge_2020_05/mod.rs:81:5
[INFO] [stderr]    |
[INFO] [stderr] 81 |     pub fn bitwise_complement_v2(n: i32) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `first_uniq_char`
[INFO] [stderr]   --> src/challenge_2020_05/mod.rs:85:5
[INFO] [stderr]    |
[INFO] [stderr] 85 |     pub fn first_uniq_char(s: String) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `majority_element`
[INFO] [stderr]   --> src/challenge_2020_05/mod.rs:99:5
[INFO] [stderr]    |
[INFO] [stderr] 99 |     pub fn majority_element(nums: Vec<i32>) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `check_straight_line`
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:117:5
[INFO] [stderr]     |
[INFO] [stderr] 117 |     pub fn check_straight_line(coordinates: Vec<Vec<i32>>) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `is_perfect_square`
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:137:5
[INFO] [stderr]     |
[INFO] [stderr] 137 |     pub fn is_perfect_square(num: i32) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `is_perfect_square_v2`
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:152:5
[INFO] [stderr]     |
[INFO] [stderr] 152 |     pub fn is_perfect_square_v2(num: i32) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `find_judge`
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:171:5
[INFO] [stderr]     |
[INFO] [stderr] 171 |     pub fn find_judge(n: i32, trust: Vec<Vec<i32>>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `find_judge_v2`
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:193:5
[INFO] [stderr]     |
[INFO] [stderr] 193 |     pub fn find_judge_v2(n: i32, trust: Vec<Vec<i32>>) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `flood_fill`
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:205:5
[INFO] [stderr]     |
[INFO] [stderr] 205 |     pub fn flood_fill(mut image: Vec<Vec<i32>>, sr: i32, sc: i32, new_color: i32) -> Vec<Vec<i32>> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `fill`
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:206:12
[INFO] [stderr]     |
[INFO] [stderr] 206 |         fn fill(image: &mut Vec<Vec<i32>>, r: usize, c: usize, new_color: i32, old_color: i32) {
[INFO] [stderr]     |            ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/contest_184/mod.rs:6:8
[INFO] [stderr]   |
[INFO] [stderr] 6 | struct Solution;
[INFO] [stderr]   |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `string_matching`
[INFO] [stderr]   --> src/contest_184/mod.rs:10:5
[INFO] [stderr]    |
[INFO] [stderr] 10 |     pub fn string_matching(mut words: Vec<String>) -> Vec<String> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `entity_parser`
[INFO] [stderr]   --> src/contest_184/mod.rs:30:5
[INFO] [stderr]    |
[INFO] [stderr] 30 |     pub fn entity_parser(text: String) -> String {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `process_queries`
[INFO] [stderr]   --> src/contest_184/mod.rs:65:5
[INFO] [stderr]    |
[INFO] [stderr] 65 |     pub fn process_queries(queries: Vec<i32>, m: i32) -> Vec<i32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `num_of_ways`
[INFO] [stderr]   --> src/contest_184/mod.rs:86:5
[INFO] [stderr]    |
[INFO] [stderr] 86 |     pub fn num_of_ways(n: i32) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/contest_185/mod.rs:7:8
[INFO] [stderr]   |
[INFO] [stderr] 7 | struct Solution;
[INFO] [stderr]   |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `reformat`
[INFO] [stderr]   --> src/contest_185/mod.rs:10:5
[INFO] [stderr]    |
[INFO] [stderr] 10 |     pub fn reformat(s: String) -> String {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `display_table`
[INFO] [stderr]   --> src/contest_185/mod.rs:40:5
[INFO] [stderr]    |
[INFO] [stderr] 40 |     pub fn display_table(orders: Vec<Vec<String>>) -> Vec<Vec<String>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `display_table_v2`
[INFO] [stderr]   --> src/contest_185/mod.rs:78:5
[INFO] [stderr]    |
[INFO] [stderr] 78 |     pub fn display_table_v2(orders: Vec<Vec<String>>) -> Vec<Vec<String>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/contest_186/mod.rs:6:8
[INFO] [stderr]   |
[INFO] [stderr] 6 | struct Solution;
[INFO] [stderr]   |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `max_score`
[INFO] [stderr]  --> src/contest_186/mod.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 |     pub fn max_score(s: String) -> i32 {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `find_diagonal_order`
[INFO] [stderr]   --> src/contest_186/mod.rs:34:5
[INFO] [stderr]    |
[INFO] [stderr] 34 |     pub fn find_diagonal_order(nums: Vec<Vec<i32>>) -> Vec<i32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/contest_187/mod.rs:7:8
[INFO] [stderr]   |
[INFO] [stderr] 7 | struct Solution;
[INFO] [stderr]   |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `dest_city`
[INFO] [stderr]   --> src/contest_187/mod.rs:10:5
[INFO] [stderr]    |
[INFO] [stderr] 10 |     pub fn dest_city(paths: Vec<Vec<String>>) -> String {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `k_length_apart`
[INFO] [stderr]   --> src/contest_187/mod.rs:23:5
[INFO] [stderr]    |
[INFO] [stderr] 23 |     pub fn k_length_apart(nums: Vec<i32>, k: i32) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/contest_188/mod.rs:4:8
[INFO] [stderr]   |
[INFO] [stderr] 4 | struct Solution;
[INFO] [stderr]   |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `build_array`
[INFO] [stderr]  --> src/contest_188/mod.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 |     pub fn build_array(target: Vec<i32>, n: i32) -> Vec<String> {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/easy/mod.rs:6:8
[INFO] [stderr]   |
[INFO] [stderr] 6 | struct Solution {}
[INFO] [stderr]   |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `two_sum`
[INFO] [stderr]   --> src/easy/mod.rs:10:5
[INFO] [stderr]    |
[INFO] [stderr] 10 |     pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/medium/mod.rs:4:8
[INFO] [stderr]   |
[INFO] [stderr] 4 | struct Solution {}
[INFO] [stderr]   |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `three_sum`
[INFO] [stderr]  --> src/medium/mod.rs:8:5
[INFO] [stderr]   |
[INFO] [stderr] 8 |     pub fn three_sum(mut nums: Vec<i32>) -> Vec<Vec<i32>> {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 95 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stderr]  --> src/common/tree_node.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::borrow::BorrowMut;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/contest_184/mod.rs:92:12
[INFO] [stderr]    |
[INFO] [stderr] 92 |        for i in 2..=n {
[INFO] [stderr]    |            ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:103:33
[INFO] [stderr]     |
[INFO] [stderr] 103 |                 Entry::Occupied(mut o) if *o.get() >= nums.len() / 2 => {
[INFO] [stderr]     |                                 ----^
[INFO] [stderr]     |                                 |
[INFO] [stderr]     |                                 help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/challenge_2020_05/mod.rs:109:31
[INFO] [stderr]     |
[INFO] [stderr] 109 |                 Entry::Vacant(mut v) => {
[INFO] [stderr]     |                               ----^
[INFO] [stderr]     |                               |
[INFO] [stderr]     |                               help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `new`
[INFO] [stderr]   --> src/challenge_2020_04/tree_node.rs:14:5
[INFO] [stderr]    |
[INFO] [stderr] 14 |     pub fn new(val: i32) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `find_diagonal_order`
[INFO] [stderr]   --> src/contest_186/mod.rs:34:5
[INFO] [stderr]    |
[INFO] [stderr] 34 |     pub fn find_diagonal_order(nums: Vec<Vec<i32>>) -> Vec<i32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 11 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.06s
[INFO] running `"docker" "inspect" "0c69f4905b1da216140d8fba7d02bbf80982e830d2c842802ea2e9ed1f3423fe"`
[INFO] running `"docker" "rm" "-f" "0c69f4905b1da216140d8fba7d02bbf80982e830d2c842802ea2e9ed1f3423fe"`
[INFO] [stdout] 0c69f4905b1da216140d8fba7d02bbf80982e830d2c842802ea2e9ed1f3423fe