BJFU 质数相关

/*
 BJFU  质数相关
 http://101.200.220.237/contest/19/problem/116/
 二分图
 按质因数奇偶性建立二分图
 *
 *
 */
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <vector>
#include <queue>
//#define test
using namespace std;
const int Nmax=500005;
int n;
int num[Nmax];
int s1[Nmax];
int s2[Nmax];
int cnt1;
int cnt2;
int match[Nmax];
int book[Nmax];
int is_prime[Nmax];
int prime[Nmax];
int prime_cnt;
vector<int> v1[Nmax],v2[Nmax];
int is(int n)
{
    int ans=0;
    for(int i=1;i<=prime_cnt;i++)
    {
        if(prime[i]>n)
            break;
        if(n%prime[i]==0)
        {
            while(n%prime[i]==0)
            {
                ans++;
                n/=prime[i];
            }
        }
    }

    //if(is_prime[n])
        //return 1;
    //for(int i=2;i*i<=n;i++)
    //{
        //while(n%i==0)
        //{
            //ans++;
            //n/=i;
        //}
    //}
    return ans&1;
}

int dfs(int v)
{
   for(int i=0;i<v1[v].size();i++)
   {
       int u=v1[v][i];
       if(book[u])
           continue;
       book[u]=1;
       if(match[u]==-1 || dfs(match[u]))
       {
           match[u]=v;
           return 1;
       }
   }
   return 0;
}

void init()
{
    for(int i=1;i<=cnt1;i++)
        v1[i].clear();
    for(int i=1;i<=cnt2;i++)
        v2[i].clear();
    for(int i=1;i<=cnt1;i++)
    {
        for(int j=1;j<=cnt2;j++)
        {
            if(s1[i]%s2[j]==0 && is_prime[s1[i]/s2[j]])
            {
                v1[i].push_back(j);
                v2[j].push_back(i);
            }
            else if(s2[j]%s1[i]==0 && is_prime[s2[j]/s1[i]])
            {
                v1[i].push_back(j);
                v2[j].push_back(i);
            }
        }
    }
    for(int i=1;i<=cnt2;i++)
        match[i]=-1;
}

void get_prime()
{
    for(int i=2;i<Nmax;i++)
        is_prime[i]=1;
    for(int i=2;i<Nmax;i++)
        if(is_prime[i])
        {
            prime[++prime_cnt]=i;
            for(int j=2;j*i<Nmax;j++)
                is_prime[i*j]=0;
        }
}

int main()
{
    #ifdef test
    freopen("6.test.in","r",stdin);
    #endif
    int t;
    scanf("%d",&t);
    get_prime();
    for(int ttt=1;ttt<=t;ttt++)
    {
        printf("Case #%d: ",ttt);
        scanf("%d",&n);
        cnt1=cnt2=0;
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&num[i]);
            if(num[i]==1)
            {
                s2[++cnt2]=num[i];
                continue;
            }
            if(is(num[i]))
                s1[++cnt1]=num[i];
            else
                s2[++cnt2]=num[i];
        }
#ifdef tesst
        for(int i=1;i<=cnt1;i++)
            printf("%d ",s1[i]);
        printf("
");
        for(int j=1;j<=cnt2;j++)
            printf("%d ",s2[j]);
        printf("
");
#endif
        init();
        int ans=0;
        for(int i=1;i<=cnt1;i++)
        {
            for(int j=1;j<=cnt2;j++)
                book[j]=0;
            if(dfs(i))
                ans++;
        }
        printf("%d
",n-ans);
    }
    return 0;
}