PATA1128题解

//
//  main.cpp
//  PATA1128
//
//  Created by Phoenix on 2018/2/25.
//  Copyright © 2018年 Phoenix. All rights reserved.
//

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int maxn = 1010;

int main(int argc, const char * argv[]) {
    int n;
    scanf("%d", &n);
    for(int i = 0; i < n; i++) {
        bool flag = true;
        int table1[maxn * 2] = {0}, table2[maxn * 2] = {0};
        int row[maxn] = {0};
        int k;
        scanf("%d", &k);
        for(int j = 1; j <= k; j++) {
            int a;
            scanf("%d", &a);
            if(row[a] == 0) row[a] = 1;
            else flag = false;
            if(table1[j + a] == 0) table1[j + a] = 1;
            else flag = false;
            if(table2[k + 1 - j + a] == 0) table2[k + 1 - j + a] = 1;
            else flag = false;
        }
        if(flag) printf("YES\n");
        else printf("NO\n");
    }
    return 0;
}