algorithmic_tree_cutter.cpp

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

int main()
{
  long long n, h, k;
  cin >> n >> h >> k;

  long long hi[n];
  long long gi[n];

  for (int i = 0; i < n; i++)
  {
    cin >> hi[i];
  }

  for (int i = 0; i < n; i++)
  {
    cin >> gi[i];
  }

  // binary search
  long long r = 1e9;
  long long l = 0;

  long long ans = 1e9;

  while (l <= r)
  {
    long long t = floor((l + r) / 2);

    long long woodCanCollect = 0;

    for (long long i = 0; i < n; i++)
    {
      long long heightNow = hi[i] + (gi[i] * t);
      if (heightNow > h)
      {
        woodCanCollect += heightNow;
      }
    }

    if (woodCanCollect >= k)
    {
      ans = t;
      r = t - 1;
    }
    else
    {
      l = t + 1;
    }
  }

  cout << ans;
}