1899E - Queue Sort - CodeForces Solution

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ll> vll;
#define pb push_back
#define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define all(x) (x).begin(), (x).end()
#define oo 2e9+7
const int MOD = 1e9 + 7;
 

void solve(int oops)
{
    int n;
    cin >> n;
    vi v(n);
    int mn = oo;
    for (int i = 0; i < n; i++)
    {
        cin >> v[i];
        mn = min(mn, v[i]);
    }
    int it = 0;
    for (int i = 0; i < n; i++)
    {
        if(v[i] == mn){

            it = i;
            break;
        }
    }
    for (int i = it+1; i < n; i++)
    {
        if(v[i] < v[i-1]){
            cout << -1 << endl;
            return;
        }
    }
    
    cout << it << endl;
}
 
int main()
{
    fast_cin();
    #ifndef ONLINE_JUDGE
       freopen("input.txt", "r", stdin);
       freopen("output.txt", "w", stdout);
    #endif
    int t = 1;
    cin >> t;
    int oops = 1;
    while(t--){
       solve(oops);
       oops++;
    }
    return 0;
}