CodeForces 275C k-Multiple Free Set

C. k-Multiple Free Set
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
A k-multiple free set is a set of integers where there is no pair of integers where one is equal to another integer multiplied by k. That is, there are no two integers x and y (x y) from the set, such that y = x·k.
You're given a set of n distinct positive integers. Your task is to find the size of it's largest k-multiple free subset.
Input
The first line of the input contains two integers n and k (1 ≤ n ≤ 105, 1 ≤ k ≤ 109). The next line contains a list of n distinct positive integers a1, a2, ..., an (1 ≤ ai ≤ 109).
All the numbers in the lines are separated by single spaces.
Output
On the only line of the output print the size of the largest k-multiple free subset of {a1, a2, ..., an}.
Sample test(s)
input

6 2
2 3 6 5 4 10

output

3

Note
In the sample input one of the possible maximum 2-multiple free subsets is {4, 5, 6}.
이분 검색
(좀 못생겼다!)

#include
#include
using namespace std;
long long a[100010],vis[100010];
long long ans,n,k;
void search(long long x)
{
  long long l=1,r=n;
  while(lx)
    {
      r=mid;
    }
    else if(a[mid]1)
  {
    printf("%I64d
",n);
    return 0;
  }
  sort(a+1,a+n+1);
  for(long long i=1;i<=n;i++)vis[i]=0;
  ans=n;
  for(long long i=1;i<=n;i++)
  {
    if(!vis[i])search(a[i]*k);
  }
  printf("%I64d
",ans);
  return 0;
}