SDUT 3258 Square Number 简单数学

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;
typedef long long LL;
const int N=1e6+5;
const int INF=0x3f3f3f3f;
int vis[N],prime[1005],cnt;
void getprime(){
  bool v[1020];
  memset(v,0,sizeof(v));
  for(int i=2;i*i<=1000;++i){
    if(v[i])continue;
    for(int j=i*i;j<=1000;j+=i)
      v[j]=1;
  }
  for(int i=2;i<=1000;++i)
    if(!v[i])prime[++cnt]=i;
}
int main(){
    int T,n;
    getprime();
    scanf("%d",&T);
    while(T--){
      memset(vis,0,sizeof(vis));
      scanf("%d",&n);
      LL ans=0;
      for(int i=1;i<=n;++i){
        int t;scanf("%d",&t);
        for(int j=1;j<=cnt&&prime[j]<=t/prime[j];++j){
            int tmp=0;
            while(t%prime[j]==0)t/=prime[j],++tmp;
            if(tmp&1)t*=prime[j];
        }
        ans+=vis[t];
        // printf("%I64d\n",ans);
        ++vis[t];
      }
      printf("%lld\n",ans);
    }
    return 0;
}