[leetcode 189] Rotate Array
Given an array, rotate the array to the right by k steps, where k is non-negative. Follow up: Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem. Could you do it in-place with O(1) extra space? Example 1: Input: nums = [1,2,3,4,5,6,7], k = 3 Output: [5,6,7,1,2,3,4] Explanation: rotate 1 steps to the right: [7,1,2,3,4,5,6] rotate 2 steps to the ..
2020. 11. 16.
[leetcode 54] Spiral Matrix
Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. Example 1: Input: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] Output: [1,2,3,6,9,8,7,4,5] Example 2: Input: [ [1, 2, 3, 4], [5, 6, 7, 8], [9,10,11,12] ] Output: [1,2,3,4,8,12,11,10,9,5,6,7] 문제 풀이: 구현문제 - 아래 그림대로 구현한다. 맨 위 row와 오른쪽 col을 돌고 아래 row와 왼쪽 col를 돈다. class Solution { public: vector spir..
2020. 11. 10.
[leetcode 73] Set Matrix Zeroes
Given an m x n matrix. If an element is 0, set its entire row and column to 0. Do it in-place. Follow up: A straight forward solution using O(mn) space is probably a bad idea. A simple improvement uses O(m + n) space, but still not the best solution. Could you devise a constant space solution? Example 1: Input: matrix = [[1,1,1],[1,0,1],[1,1,1]] Output: [[1,0,1],[0,0,0],[1,0,1]] Example 2: Input..
2020. 11. 7.
