矩阵顺时针反转
public class A066_rotateMatrix {
public static int[][] rotateMatrix(int[][] mat, int n) {
int length = mat.length;
//矩阵转置，显示对角线交换
for (int i = 0; i < length; i++) {
for (int j = 0; j < i; j++) {
//交换上三角与下三角对应的元素
int temp = mat[i][j];
mat[i][j] = mat[j][i];
mat[j][i] = temp;
}
}
//然后是每行翻转
for (int i = 0; i < length; i++) {
for (int j = 0; j < length / 2; j++) {
int temp = mat[i][j];
mat[i][j] = mat[i][length - j - 1];
mat[i][length - j - 1] = temp;
}
}
return mat;
}
}