UVa 11526 - H(n)

Accepted date: 2013-02-04
Ranking (as of 2013-02-05): 121
Language: C++

/*
  UVa 11526 - H(n)

  To build using Visual Studio 2008:
    cl -EHsc -O2 UVa_11526_Hn.cpp
*/

#include <cstdio>
#include <cmath>

long long H(int n)
{
  if (n < 0)
    return 0;
  if (n == 1)
    return 1;
  long long result = n;
  int cur_divisor = 2, cur_quoitent, prev_divisor = 1, prev_quoitent = n;
  while (true) {
    cur_quoitent = n / cur_divisor;
    result +=
      static_cast<long long>(prev_quoitent - cur_quoitent) * prev_divisor;
    if (cur_quoitent >= cur_divisor)
      result += cur_quoitent;
    if (cur_quoitent <= cur_divisor)
      break;
    prev_divisor = cur_divisor++;
    prev_quoitent = cur_quoitent;
  }
  return result;
}

int main()
{
  int t;
  scanf("%d",& t);
  while (t--) {
    int n;
    scanf("%d", &n);
    printf("%lld\n", H(n));
  }
  return 0;
}