Dmitrii Volyx

![https://leetcode.com/problems/sort-the-matrix-diagonally/] A matrix diagonal is a diagonal line of cells starting from some cell in either the topmost row or leftmost column and going in the bottom-right direction until reaching the matrix’s end. For example, the matrix diagonal starting from mat[2][0], where mat is a 6 x 3 matrix, includes cells mat[2][0], mat[3][1], and mat[4][2]. Given an m x n matrix mat of integers, sort each matrix diagonal in ascending order and return the resulting matrix. ...

![https://leetcode.com/problems/sort-colors/] Given an array nums with n objects colored red, white, or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white, and blue. We will use the integers 0, 1, and 2 to represent the color red, white, and blue, respectively. Example 1: Input: nums = [2,0,2,1,1,0] Output: [0,0,1,1,2,2] Example 2: Input: nums = [2,0,1] Output: [0,1,2] Example 3: Input: nums = [0] Output: [0] Example 4: Input: nums = [1] Output: [1] Constraints: ...

![https://leetcode.com/problems/merge-intervals/] Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cover all the intervals in the input. Example 1: Input: intervals = [[1,3],[2,6],[8,10],[15,18]] Output: [[1,6],[8,10],[15,18]] Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6]. Example 2: Input: intervals = [[1,4],[4,5]] Output: [[1,5]] Explanation: Intervals [1,4] and [4,5] are considered overlapping. Constraints: ...

![https://leetcode.com/problems/largest-values-from-labels/] We have a set of items: the i-th item has value values[i] and label labels[i]. Then, we choose a subset S of these items, such that: |S| <= num_wanted For every label L, the number of items in S with label L is <= use_limit. Return the largest possible sum of the subset S. Example 1: Input: values = [5,4,3,2,1], labels = [1,1,2,2,3], num_wanted = 3, use_limit = 1 Output: 9 Explanation: The subset chosen is the first, third, and fifth item. Example 2: Input: values = [5,4,3,2,1], labels = [1,3,3,3,2], num_wanted = 3, use_limit = 2 Output: 12 Explanation: The subset chosen is the first, second, and third item. Example 3: Input: values = [9,8,8,7,6], labels = [0,0,0,1,1], num_wanted = 3, use_limit = 1 Output: 16 Explanation: The subset chosen is the first and fourth item. Example 4: Input: values = [9,8,8,7,6], labels = [0,0,0,1,1], num_wanted = 3, use_limit = 2 Output: 24 Explanation: The subset chosen is the first, second, and fourth item. Note: ...

![https://leetcode.com/problems/search-a-2d-matrix-ii/] Write an efficient algorithm that searches for a target value in an m x n integer matrix. The matrix has the following properties: Integers in each row are sorted in ascending from left to right. Integers in each column are sorted in ascending from top to bottom. Example 1: Input: matrix = [[1,4,7,11,15],[2,5,8,12,19],[3,6,9,16,22],[10,13,14,17,24],[18,21,23,26,30]], target = 5 Output: true Example 2: Input: matrix = [[1,4,7,11,15],[2,5,8,12,19],[3,6,9,16,22],[10,13,14,17,24],[18,21,23,26,30]], target = 20 Output: false Constraints: ...

![https://leetcode.com/problems/widest-vertical-area-between-two-points-containing-no-points/] Given n points on a 2D plane where points[i] = [xi, yi], Return the widest vertical area between two points such that no points are inside the area. A vertical area is an area of fixed-width extending infinitely along the y-axis (i.e., infinite height). The widest vertical area is the one with the maximum width. Note that points on the edge of a vertical area are not considered included in the area. ...

![https://leetcode.com/problems/k-closest-points-to-origin/] We have a list of points on the plane. Find the K closest points to the origin (0, 0). (Here, the distance between two points on a plane is the Euclidean distance.) You may return the answer in any order. The answer is guaranteed to be unique (except for the order that it is in.) Example 1: Input: points = [[1,3],[-2,2]], K = 1 Output: [[-2,2]] Explanation: The distance between (1, 3) and the origin is sqrt(10). The distance between (-2, 2) and the origin is sqrt(8). Since sqrt(8) < sqrt(10), (-2, 2) is closer to the origin. We only want the closest K = 1 points from the origin, so the answer is just [[-2,2]]. Example 2: Input: points = [[3,3],[5,-1],[-2,4]], K = 2 Output: [[3,3],[-2,4]] (The answer [[-2,4],[3,3]] would also be accepted.) Note: ...

![https://leetcode.com/problems/majority-element/] Given an array nums of size n, return the majority element. The majority element is the element that appears more than ⌊n / 2⌋ times. You may assume that the majority element always exists in the array. Example 1: Input: nums = [3,2,3] Output: 3 Example 2: Input: nums = [2,2,1,1,1,2,2] Output: 2 Constraints: n == nums.length 1 <= n <= 5 * 104 -231 <= nums[i] <= 231 - 1 Follow-up: Could you solve the problem in linear time and in O(1) space? ...

![https://leetcode.com/problems/kth-largest-element-in-an-array/] Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element. Example 1: Input: [3,2,1,5,6,4] and k = 2 Output: 5 Example 2: Input: [3,2,3,1,2,4,5,5,6] and k = 4 Output: 4 Note: You may assume k is always valid, 1 ≤ k ≤ array’s length. class Solution { public int findKthLargest(int[] nums, int k) { int lo = 0; int hi = nums.length - 1; k = nums.length - k; while (lo < hi) { int j = partition(nums, lo, hi); if (j < k) { lo = j + 1; } else if (j > k) { hi = j - 1; } else { return nums[k]; } } return nums[k]; } int partition(int[] a, int lo, int hi) { int i = lo; int j = hi + 1; while (true) { while (a[++i] < a[lo]) { if (i == hi) break; } while (a[lo] < a[--j]) { if (j == lo) break; } if (i >= j) break; swap(a, i, j); } swap(a, lo, j); return j; } void swap(int[] a, int i, int j) { int temp = a[i]; a[i] = a[j]; a[j] = temp; } }

![https://leetcode.com/problems/shuffle-string/] Given a string s and an integer array indices of the same length. The string s will be shuffled such that the character at the ith position moves to indices[i] in the shuffled string. Return the shuffled string. Example 1: Input: s = "codeleet", indices = [4,5,6,7,0,2,1,3] Output: "leetcode" Explanation: As shown, "codeleet" becomes "leetcode" after shuffling. Example 2: Input: s = "abc", indices = [0,1,2] Output: "abc" Explanation: After shuffling, each character remains in its position. Example 3: Input: s = "aiohn", indices = [3,1,4,2,0] Output: "nihao" Example 4: Input: s = "aaiougrt", indices = [4,0,2,6,7,3,1,5] Output: "arigatou" Example 5: Input: s = "art", indices = [1,0,2] Output: "rat" Constraints: ...