【牛客题霸题解】顺时针旋转矩阵

观察可以发现，原矩阵(x,y)位置的数字旋转完成了以后会在(y)(n-1-x)位置。
c++

class Solution {
public:
    vector<vector<int> > rotateMatrix(vector<vector<int> > mat, int n) {
        vector<vector<int> > ans(n);
        for(int i = 0 ; i < n ; i++)
        {
            ans[i].resize(n);
        }
        for(int x = 0 ; x < n ;x++)
        {
            for(int y = 0 ; y < n ; y++)
            {
                ans[y][n-1-x] = mat[x][y];
            }
        }
        return ans;
    }
};

java

import java.util.*;

public class Solution {
    public int[][] rotateMatrix(int[][] mat, int n) {
        int ans[][] = new int[n][n];
        for(int x = 0 ; x < n ;x++)
        {
            for(int y = 0 ; y < n ; y++)
            {
                ans[y][n-1-x] = mat[x][y];
            }
        }
        return ans;
    }
}

python

class Solution:
    def rotateMatrix(self, mat, n):
        ans = [[0]*n for e in range(n)]
        for x in range(n):
            for y in range(n):
                ans[y][n-1-x] = mat[x][y]
        return ans