1856A - Tales of a Sort - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;

void solve() {
    int n;
    cin>>n;
    vector<int> arr(n);
    for(int i=0;i<n;i++) cin>>arr[i];
    
    reverse(arr.begin(), arr.end());
    int ind = 0;
    for(int i=0;i<n-1;i++) {
        if (arr[i] >= arr[i+1]) ind++;
        else break;
    }
    int maxi = arr[ind];
    for(int i=ind;i<n;i++) {
        maxi = max(maxi, arr[i]);
    }
    if (ind == n-1) cout<<0<<endl;
    else cout<<maxi<<endl;
    return;
}

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