NDIV.cpp

#include<iostream>
#include<cmath>
#include<stdio.h>
using namespace std;
#define MAX 31627
#define sq 178
int check[32000];
int prime[10000];
#define ll long long
ll temp;
void s()
{
    ll i,j;
    for(i=3;i<=sq;i++)
    {
      if(!check[i])
      {
        for(j=i*i;j<MAX+1;j+=i)
        {
          check[j]=1;
        }
      }
}
  prime[0]=2;
  j=1;
  for(i=3;i<=MAX;i+=2)
  {
    if(!check[i])
    {
      prime[j]=i;
      j++;
    }
  }
}
int main()
{
  s();
  ll a,b,n,i,j,k,r=0,ans,coun=0;
  scanf("%lld%lld%lld",&a,&b,&n);
  for(i=a;i<=b;i++)
  {
    temp=i;
    k=0;
    coun=0;
    ans=1;
    for(j=prime[k];j*j<=temp;j=prime[k++])
    {
      coun=0;
      while(temp%j==0)
      {
        temp/=j;
        coun++;
      }
      ans*=coun+1;
    }
    if(temp!=1)
    {
      ans*=2;
    }
    if(ans==n)
    {
      r++;
    }
  }
  printf("%lld\n",r);
  return 0;
}