題目
You are given an n x n 2D matrix representing an image.
Rotate the image by 90 degrees (clockwise).
一個n*n的二維數(shù)組俯艰，代表一張圖片侍匙，將這張圖片順時針旋轉90°后雾叭，返回旋轉后的二維數(shù)組
- 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]
]
- 思路
原數(shù)組取其轉置矩陣壹无，然后把每行的數(shù)字翻轉可得到結果
1 2 3 1 4 7 7 4 1
4 5 6 --> 2 5 8 --> 8 5 2
7 8 9 3 6 9 9 6 3
- 解法
function rotateImage(matrix){
const len = matrix.length
for(var i = 0; i < len; i++){
for(var j = i + 1; j < len; j++){
let temp = arr[i][j]
arr[i][j] = arr[j][i]
arr[j][i] = temp
}
}
for(i = 0; i < len; i++){
matrix[i].reverse()
}
return matrix
}
