UVA 10892 LCM Cardinality (分解因数＋暴力)

#include <cstdio>
#include <cstring>
#define ll long long
int const MAX = 1e5;
int const LIM = 2e9;
int fac[MAX], cnt, n;

int gcd(int a, int b)
{
    while(b)
    {
        int tmp = a;
        a = b;
        b = tmp % b;
    }
    return a;
}

ll lcm(int a, int b)
{
    return (ll) a * b / gcd(a, b);
}

void cal()
{
    cnt = 0;
    for(int i = 1; i * i <= n; i++)
    {
        if(n % i == 0)
        {
            fac[cnt++] = i;
            fac[cnt++] = n / i;
        }
        if(fac[cnt - 1] == fac[cnt - 2])
            cnt --;
    }
}

int main()
{
    while(scanf("%d", &n) != EOF && n)
    {
        cal();
        int ans = 0;
        for(int i = 0; i < cnt; i++)
            for(int j = i; j < cnt; j++)
                if(lcm(fac[i], fac[j]) == n)
                    ans ++;
        printf("%d %d\n", n, ans);
    }
}