Rotate Image

将图片旋转90°，实际上就是在操作数组，感觉实际中canvas可以用到。

 

 

 

public class Solution {
    public void rotate(int[][] matrix) {
        if (matrix.length == 1) {
            return;
        } else {
            int n = matrix.length;
            for (int i = 0; i < n; i++) {
                for (int a = 0; a < i; a++) {
                    matrix[a][i] = matrix[a][i] + matrix[i][a];
                    matrix[i][a] = matrix[a][i] - matrix[i][a];
                    matrix[a][i] = matrix[a][i] - matrix[i][a];
                }
            }
            int max = (n & 1) == 1 ? n - 1 : n;
            for (int i = 0; i < n; i++) {
                for (int a = 0; a < max - a; a++) {
                    matrix[i][a] = matrix[i][a] + matrix[i][n - a - 1];
                    matrix[i][n - a - 1] = matrix[i][a] - matrix[i][n - a - 1];
                    matrix[i][a] = matrix[i][a] - matrix[i][n - a - 1];
                }
            }
        }
    }
}