Submission #1167281

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Source Code Expand

#include <bits/stdc++.h>

#define each(i, c) for (auto& i : c)
#define unless(cond) if (!(cond))

using namespace std;

typedef long long int lli;
typedef unsigned long long ull;
typedef complex<double> point;

template<typename P, typename Q>
ostream& operator << (ostream& os, pair<P, Q> p)
{
  os << "(" << p.first << "," << p.second << ")";
  return os;
}

int main(int argc, char *argv[])
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  lli n;
  while (cin >> n) {
    lli small = 1;
    lli large = 1LL << 30;
    while (small + 1 < large) {
      lli mid = (small + large) / 2;
      lli x = mid * (mid - 1) / 2;
      if (n <= x) large = mid;
      else small = mid;
    }
    // cout << make_pair(small, large) << endl;
    cout << small << endl;
  }
  
  return 0;
}

Submission Info

Judge Result