11558 The Game of Death

이거 전에 풀어서 맞춘 것 같은데??? 왜 또 푸는 것 같지

 

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <functional>
#include <string>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <map>
#include <cmath>
#include <cstring>
#include <bitset>
#include <stdio.h>
#include <math.h>

#define xx first
#define yy second
#define all(x) (x).begin(), (x).end()

using namespace std;
using i64 = long long int;
using ii = pair<int, int>;
using iis = pair<int, string>;
using ii64 = pair<i64, i64>;
using iii = tuple<int, int, int>;

void solve() {
    int n;
    scanf("%d", &n);
    
    vector<int> v(n + 1);
    for (int i = 1; i <= n; i++)
        scanf("%d", &v[i]);
    
    vector<bool> check(n + 1);
    
    int next = v[1];
    int cnt = 1;
    while (!check[next]) {
        if (next == n) {
            printf("%d\n", cnt);
            return;
        }
        
        check[next] = true;
        next = v[next];
        cnt++;
    }
    
    printf("0\n");
}

int main() {
    int t;
    scanf("%d", &t);
    
    for (int i = 0; i < t; i++)
        solve();
    
    return 0;
}