Spy Detected.cpp

// https://codeforces.com/contest/1512/problem/A
#include <bits/stdc++.h>

#define fi          first
#define se          second
#define pb          push_back
#define mp          make_pair
#define ll          long long
#define pll         pair<long, long>
#define vll         vector<long long>
#define inf         1e18
#define range(a,b)  substr(a,b-a+1)
#define FIO         ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)

using namespace std;

int main()
{
    FIO;

    #ifndef ONLINE_JUDGE
    //remove this piece of code when this has to be submitted in kickstart, coding ninjas
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    //freopen is used to associate a file with stdin or stdout stream in C++
    #endif

    ll t;
    cin >> t;
    while (t--) {
        ll n;
        cin >> n;
        vll arr(n);
        for (ll i = 0; i < n; i++)
            cin >> arr[i];
        if (arr[0] == arr[1]) {
            for (ll i = 2; i < n; i++)
                if (arr[i] != arr[0]) {
                    cout << i + 1 << "\n";
                    break;
                }
        }
        else {
            if (arr[0] == arr[2])
                cout << 2 << "\n";
            else
                cout << 1 << "\n";
        }
        
    }

    return 0;
}