48. 旋转图像

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