求一个数的阶乘的结果的位数

#include<iostream>using namespace std;double fac(int);int main(){   int k,n;   cin >> n;   while ( n--)   {   int cunt = 1;   double t,s;   cin >> k;   s = fac(k);   t = s / 10;   while ( t!=0)   {     t = t / 10;    ++cunt;   }   cout << cunt<<endl;   }   return 0;}double fac(int m){double q;if (m == 1)q = 1;else{if (m > 1)q = m*fac(m - 1);elsereturn 0;}return q;}