31, 217, 231, 402

Author: safrannn

src/_0031_next_permutation.rs

@@ -0,0 +1,29 @@
+struct Solution;
+
+impl Solution {
+ pub fn next_permutation(nums: &mut Vec<i32>) {
+ let (mut i, mut switched) = (nums.len() - 1, false);
+ while i > 0 && nums[i - 1] >= nums[i] {
+ i -= 1;
+ }
+ if i != 0 {
+ let (pivot, mut smallest_larger_index) = (nums[i - 1], i);
+ for j in i..nums.len() {
+ if nums[j] > pivot && nums[j] <= nums[smallest_larger_index] {
+ smallest_larger_index = j;
+ }
+ }
+ nums.swap(i - 1, smallest_larger_index);
+ nums[i..].sort()
+ } else {
+ nums.sort()
+ }
+ }
+}
+
+#[test]
+fn test() {
+ assert_eq!(Solution::next_permutation(vec![1, 2, 3]), vec![1, 3, 2]);
+ assert_eq!(Solution::next_permutation(vec![3, 2, 1]), vec![1, 2, 3]);
+ assert_eq!(Solution::next_permutation(vec![1, 1, 5]), vec![1, 5, 1]);
+}

src/_0217_contains_duplicate.rs

@@ -0,0 +1,26 @@
+use std::collections::HashSet;
+
+struct Solution;
+
+impl Solution {
+ pub fn contains_duplicate(nums: Vec<i32>) -> bool {
+ let mut counter: HashSet<i32> = HashSet::new();
+ for num in &nums {
+ if counter.contains(num) {
+ return true;
+ }
+ counter.insert(*num);
+ }
+ false
+ }
+}
+
+#[test]
+fn test() {
+ assert_eq!(Solution::contains_duplicate(vec![1, 2, 3, 1]), true);
+ assert_eq!(Solution::contains_duplicate(vec![1, 2, 3, 4]), false);
+ assert_eq!(
+ Solution::contains_duplicate(vec![1, 1, 1, 3, 3, 4, 3, 2, 4, 2]),
+ true
+ );
+}

src/_0231_power_of_two.rs

@@ -0,0 +1,14 @@
+struct Solution;
+
+impl Solution {
+ pub fn is_power_of_two(n: i32) -> bool {
+ n > 0 && n & (n - 1) == 0
+ }
+}
+
+#[test]
+fn test() {
+ assert_eq!(Solution::is_power_of_two(1), true);
+ assert_eq!(Solution::is_power_of_two(16), true);
+ assert_eq!(Solution::is_power_of_two(3), false);
+}

src/_0402_remove_k_digits.rs

@@ -0,0 +1,44 @@
+struct Solution;
+
+impl Solution {
+ pub fn remove_kdigits(num: String, k: i32) -> String {
+ let mut stack = vec![];
+ let mut k = k as usize;
+ for (i, c) in num.chars().enumerate() {
+ if k > 0 {
+ while k > 0 {
+ if let Some(&last) = stack.last() {
+ if c < last {
+ stack.pop();
+ k -= 1;
+ } else {
+ break;
+ }
+ } else {
+ break;
+ }
+ }
+ }
+ stack.push(c);
+ }
+ let result = stack
+ .split_at(stack.len() - k as usize)
+ .0
+ .into_iter()
+ .collect::<String>()
+ .trim_start_matches('0')
+ .to_string();
+ if result == "" {
+ "0".to_string()
+ } else {
+ result
+ }
+ }
+}
+
+#[test]
+fn test() {
+ assert_eq!(Solution::remove_kdigits("1432219".to_string(), 3), "1219");
+ assert_eq!(Solution::remove_kdigits("10200".to_string(), 1), "200");
+ assert_eq!(Solution::remove_kdigits("10".to_string(), 2), "0");
+}

src/lib.rs

@@ -38,6 +38,8 @@ mod _0021_merge_two_sorted_lists;
 //
 mod _0022_generate_parentheses;
 //
+mod _0031_next_permutation;
+//
 mod _0034_find_first_and_last_position_of_element_in_sorted_array;
 //
 mod _0036_valid_sudoku;
@@ -136,10 +138,14 @@ mod _0213_house_robber_ii;
 //
 mod _0215_kth_largest_element_in_an_array;
 //
+mod _0217_contains_duplicate;
+//
 mod _0219_contains_duplicate_ii;
 //
 mod _0221_maximal_square;
 //
+mod _0231_power_of_two;
+//
 mod _0234_palindrome_linked_list;
 //
 mod _0238_product_of_array_except_self;
@@ -190,6 +196,8 @@ mod _0387_first_unique_character_in_a_string;
 //
 mod _0394_decode_string;
 //
+mod _0402_remove_k_digits;
+//
 mod _0404_sum_of_left_leaves;
 //
 mod _0412_fizz_buzz;