题解 | 旋转矩阵

#include <iostream>
#include <vector>
using namespace std;

int main() {
    int n;
    bool is0 = true, is90 = true, is180 = true, is270 = true;
    cin >> n;
    vector<vector <int>> arr1(n, vector<int>(n));
    vector<vector <int>> arr2(n, vector<int>(n));

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cin >> arr1[i][j];
        }
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cin >> arr2[i][j];
        }
    }

    //输出判断
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (arr2[i][j] != arr1[i][j]) {
                is0 = false;
            }
        }
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (arr2[j][n - i - 1] != arr1[i][j]) {
                is90 = false;
            }
        }
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (arr2[n-1-i][n-1-j] != arr1[i][j]) {
                //错：arr1[i][j] != arr2[n - i - 1][j]
                is180 = false;
            }
        }
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (arr2[n-1-j][i] != arr1[i][j]) {
                //错：arr1[i][j] != arr2[j][i]
                is270 = false;
            }
        }
    }

    if(is0) cout<<"0";
    else if(is90) cout<<"90";
        else if(is180) cout<<"180";
            else if(is270) cout<<"270";
                else cout<<"-1";//if(!is0&&!is90&&!is180&&!is270)
}
// 64 位输出请用 printf("%lld")