LCM的个数 (LCM Cardinality,UVa 10892)

#include <iostream>
#include <string.h>
#include <string>
#include <fstream>
#include <algorithm>
#include <stdio.h>
#include <vector>
#include <queue>
#include <set>
#include <cmath>
using namespace std;
const double eps = 1e-8;
const int INF=0x7fffffff;
#define MAXN 10000007
typedef long long LL;
LL vis[MAXN];
LL prime[MAXN];

void sieve(LL n)
{
    LL m=(LL)sqrt(n+0.5);
    memset(vis,0,sizeof(vis));
    for(LL i=2;i<=m;i++)if(!vis[i])
    for(LL j=i*i;j<=n;j+=i)vis[j]=1;
}

LL gen_prime(LL n)
{
    sieve(n);
    LL c=0;
    for(LL i=2;i<=n;i++)if(!vis[i])
        prime[c++]=i;
    return c;
}

LL gcd(LL a,LL b)
{
    return b==0?a:gcd(b,a%b);
}


int main()
{
    LL n;
    LL N=gen_prime(10000001);
    while(scanf("%lld",&n),n)
    {
        LL tempn=n;
        LL ans=1;
        for(int i=0;i<N&&n>=prime[i];i++)
        {
            int temp=0;
            while(tempn%prime[i]==0)
            {
                tempn/=prime[i];
                temp++;
            }

            ans*=(2*temp+1);
        }
        ans=(ans-1)/2+1;
        printf("%lld %lld
",n,ans);
    }
    return 0;
}

找规律……