Source Code
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define endl '\n'
#define sp ' '
#define assert(x,a) if(x){cout << a << endl;return;}
#define sortv(x)sort(x.begin(),x.end())
#define revev(x)reverse(x.begin(),x.end())
inline void fast(){
    std::ios_base::sync_with_stdio(0);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);
    }
vector<vector<int>>graph;

vector<bool>vis(100001,false);
bool sortbysec(const pair<int,int> &a,
              const pair<int,int> &b)
{
    return (a.second < b.second);
}
inline void answer(int c){assert(c==0,"NO")cout << "YES" << endl;}
void solve()
{
    ll n;cin >> n;
    if(n % 2 == 0 || n == 1)
      cout << (n * (n + 1) / 2) - n + 1<< endl;
    else
         cout << (n * (n + 1) / 2) - n<< endl;
}
int main()
{
    fast();
    ll t{ 1 };cin >> t;
  // cin.ignore();
    while (t--)
    {
        solve();
    }
}
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Study Schedule iwjx
GNU G++17
27 ms
1.3 MB
Wrong Answer