Submission

Score: 100

User: NovemNotes

Problemset: กองส้ม

Language: cpp

Time: 0.003 second

Submitted On: 2025-10-17 13:46:49

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

int main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);
    int n;cin >> n;
    vector<int> v;
    v.emplace_back(0);
    int sum=0;
    n++;
    while(n--){
        v.emplace_back(sum+n*n);
        sum+=n*n;
    }
    int m;cin >> m;
    sum-=m;
    // for(auto &x:v)cout << x << " ";cout << "\n";
    auto it = lower_bound(v.begin(),v.end(),sum);
    if(*it==sum){
        cout << it-v.begin() << "\n";
    }else{
        it--;
        cout << it-v.begin()+1 << "\n";
    }
    return 0;
}