rotateImage.js

/*
You are given an n x n 2D matrix representing an image.

Rotate the image by 90 degrees (clockwise).

Note:
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:
Given input matrix = 
[
  [1,2,3],
  [4,5,6],
  [7,8,9]
];
rotate the input matrix in-place such that it becomes:
[
  [7,4,1],
  [8,5,2],
  [9,6,3]
];

Example 2:
Given input matrix =
[
  [ 5, 1, 9,11],
  [ 2, 4, 8,10],
  [13, 3, 6, 7],
  [15,14,12,16]
]; 
rotate the input matrix in-place such that it becomes:
[
  [15,13, 2, 5],
  [14, 3, 4, 1],
  [12, 6, 8, 9],
  [16, 7,10,11]
];
*/
/**
 * @param {number[][]} matrix
 * @return {void} Do not return anything, modify matrix in-place instead.
 */
 
const rotateImage = function(matrix) {
    for (let y = 0; y < matrix.length; y++) {
        for (let x = y+1; x < matrix[y].length; x++) {
            [matrix[y][x], matrix[x][y]] = [matrix[x][y], matrix[y][x]]
        }
    }
    for (let i = 0; i < matrix.length; i++) {
        matrix[i].reverse();
    }
    console.log(matrix);
};