题解 | Sudoku

#include <iostream>
using namespace std;

void solve(){
    int a[4][4];

    for(int i = 0; i < 4; i++){
        for(int j = 0; j < 4; j++){
            cin >> a[i][j];
        }
    }

    for(int i = 0; i < 4; i++){
        int cnt1[5] = {0};
        cnt1[a[i][0]]++;
        cnt1[a[i][1]]++;
        cnt1[a[i][2]]++;
        cnt1[a[i][3]]++;
        for(int i = 1; i <= 4; i++){
            if(cnt1[i] != 1){
                cout << "NO\n";
                return;
            }
        }
    }

    for(int i = 0; i < 4; i++){
        int cnt2[5] = {0};
        cnt2[a[0][i]]++;
        cnt2[a[1][i]]++;
        cnt2[a[2][i]]++;
        cnt2[a[3][i]]++;
        for(int i = 1; i <= 4; i++){
            if(cnt2[i] != 1){
                cout << "NO\n";
                return;
            }
        }
    }
    
    for(int i = 0; i < 4; i+=2){
        for(int j = 0; j < 4; j+=2){
            int cnt3[5] = {0};
            cnt3[a[i][j]]++;
            cnt3[a[i][j+1]]++;
            cnt3[a[i+1][j]]++;
            cnt3[a[i+1][j+1]]++;
            for(int i = 1; i <= 4; i++){ 
                if(cnt3[i] != 1){
                    cout << "NO\n";
                    return;
                }
            }
        }
    }

    cout << "YES\n";

}

int main() {
    int t; cin >> t;
    while(t--){
        solve();
    }
    return 0;
}