Rotate Image

Link

https://leetcode.com/problems/rotate-image/

Deadline

Jul 24, 2022

Status

Archived

Type

Matrix

Array

문제

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.

Constraints:

n == matrix.length == matrix[i].length

1 <= n <= 20

1000 <= matrix[i][j] <= 1000

풀이

재영


/**
 * @param {number[][]} matrix
 * @return {void} Do not return anything, modify matrix in-place instead.
 */
var rotate = function(matrix) {
    const copiedMatrix = JSON.parse(JSON.stringify(matrix));
    const matrixLength = matrix.length;
    
    for (let i = 0; i < matrixLength; i += 1) {
        for (let j = 0; j < matrixLength; j += 1) {
            const row = matrixLength - 1 - j;
            const col = i;
            
            matrix[i][j] = copiedMatrix[row][col];
        };
    };
};

은찬


var rotate = function(matrix) {
    const tmp = [];
    const length = matrix.length;
    
    for(let i = 0; i < length; i++){
        tmp.push([...matrix[i]]);
    }
    
    for(let i = 0; i < length; i++){
        for(let j = 0; j < length; j++){
            matrix[i][j] = tmp[length - j - 1][i];
        }
    }
};

효성


var rotate = function(matrix) {
    const len = matrix.length;
    const copyMatrix = Array.from(Array(len), () => Array(len));
    
    for(let i = 0; i < len; i++) {
        for(let j = 0; j < len; j++) {
            copyMatrix[i][j] = matrix[i][j];
        }
    }
    
    for(let i = 0; i < len; i++) {
        for(let j = 0; j < len; j++) {
            matrix[j][len - 1 - i] = copyMatrix[i][j];
        }
    }
};