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소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise). You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation. Example 1: Input: matrix = [[1,2,3],[4,5,6],[7,8,9]] Output: [[7,4,1],[8,5,2],[9,6,3]] Example 2: Input: m..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Given the root of a binary tree, flatten the tree into a "linked list": The "linked list" should use the same TreeNode class where the right child pointer points to the next node in the list and the left child pointer is always null. The "linked list" should be in the same order as a pre-order traversal of the binary tree. Example 1: Input: root = [1,2,5,3,4,..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path. Note: You can only move either down or right at any point in time. Example 1: Input: grid = [[1,3,1],[1,5,1],[4,2,1]] Output: 7 Explanation: Because the path 1 → 3 → 1 → 1 → 1 minimizes the sum. Example 2: Inpu..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem You are given the head of a linked list. Delete the middle node, and return the head of the modified linked list. The middle node of a linked list of size n is the ⌊n / 2⌋th node from the start using 0-based indexing, where ⌊x⌋ denotes the largest integer less than or equal to x. For n = 1, 2, 3, 4, and 5, the middle nodes are 0, 1, 1, 2, and 2, respectively...

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem We are given an array asteroids of integers representing asteroids in a row. For each asteroid, the absolute value represents its size, and the sign represents its direction (positive meaning right, negative meaning left). Each asteroid moves at the same speed. Find out the state of the asteroids after all collisions. If two asteroids meet, the smaller one wi..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem You are given a string s, which contains stars *. In one operation, you can: Choose a star in s. Remove the closest non-star character to its left, as well as remove the star itself. Return the string after all stars have been removed. Note: The input will be generated such that the operation is always possible. It can be shown that the resulting string will ..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Given a 0-indexed n x n integer matrix grid, return the number of pairs (ri, cj) such that row ri and column cj are equal. A row and column pair is considered equal if they contain the same elements in the same order (i.e., an equal array). Example 1: Input: grid = [[3,2,1],[1,7,6],[2,7,7]] Output: 1 Explanation: There is 1 equal row and column pair: - (Row 2..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Given a binary array nums, you should delete one element from it. Return the size of the longest non-empty subarray containing only 1's in the resulting array. Return 0 if there is no such subarray. Example 1: Input: nums = [1,1,0,1] Output: 3 Explanation: After deleting the number in position 2, [1,1,1] contains 3 numbers with value of 1's. Example 2: Input:..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Given a binary array nums and an integer k, return the maximum number of consecutive 1's in the array if you can flip at most k 0's. Example 1: Input: nums = [1,1,1,0,0,0,1,1,1,1,0], k = 2 Output: 6 Explanation: [1,1,1,0,0,1,1,1,1,1,1] Bolded numbers were flipped from 0 to 1. The longest subarray is underlined. Example 2: Input: nums = [0,0,1,1,0,0,1,1,1,0,1,..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Given a string s and an integer k, return the maximum number of vowel letters in any substring of s with length k. Vowel letters in English are 'a', 'e', 'i', 'o', and 'u'. Example 1: Input: s = "abciiidef", k = 3 Output: 3 Explanation: The substring "iii" contains 3 vowel letters. Example 2: Input: s = "aeiou", k = 2 Output: 2 Explanation: Any substring of l..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. Implement the MinStack class: MinStack() initializes the stack object. void push(int val) pushes the element val onto the stack. void pop() removes the element on the top of the stack. int top() gets the top element of the stack. int getMin() retrieves the minimu..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Given an integer array nums, return the length of the longest strictly increasing subsequence. Example 1: Input: nums = [10,9,2,5,3,7,101,18] Output: 4 Explanation: The longest increasing subsequence is [2,3,7,101], therefore the length is 4. Example 2: Input: nums = [0,1,0,3,2,3] Output: 4 Example 3: Input: nums = [7,7,7,7,7,7,7] Output: 1 Constraints: 1

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Given the root of a binary tree, return the zigzag level order traversal of its nodes' values. (i.e., from left to right, then right to left for the next level and alternate between). Example 1: Input: root = [3,9,20,null,null,15,7] Output: [[3],[20,9],[15,7]] Example 2: Input: root = [1] Output: [[1]] Example 3: Input: root = [] Output: [] Constraints: The n..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. Example 1: Input: n = 3 Output: ["((()))","(()())","(())()","()(())","()()()"] Example 2: Input: n = 1 Output: ["()"] Constraints: 1 0) { backtrack(result, s + "(", left - 1, right); } if (right > 0) { backtrack(result, s + ")", left, right - 1); } } } back..

소스 코드는 여기 있습니다. 문제는 여기 있습니다. Problem You are given an array of strings tokens that represents an arithmetic expression in a Reverse Polish Notation. Evaluate the expression. Return an integer that represents the value of the expression. Note that: The valid operators are '+', '-', '*', and '/'. Each operand may be an integer or another expression. The division between two integers always truncat..