public int[][] rotateMatrix(int[][] mat, int n) { //1. 沿对角线交换 for(int i = 0; i < mat.length; ++i){ for(int j = 0; j < i; ++j){ int temp = mat[i][j]; mat[i][j] = mat[j][i]; mat[j][i] = temp; } } //2. 沿纵中心轴对称 for(int i=0 ; i<mat.length ; ++i){ for(int j=0 ; j<mat.length/2 ; ++j){ int temp = mat[i][j]; mat[i][j] = mat[i][n-1-j]; mat[i][n-1-j] = temp; } } return mat; }