Factorial of an integer is defined by the following function
f(0) = 1
f(n) = f(n - 1) * n, if(n > 0)
So, factorial of 5 is 120. But in different bases, the factorial may be different. For example, factorial of 5 in base 8 is 170.
In this problem, you have to find the number of digit(s) of the factorial of an integer in a certain base.
Input
Input starts with an integer T (≤ 50000), denoting the number of test cases.
Each case begins with two integers n (0 ≤ n ≤ 106) and base (2 ≤ base ≤ 1000). Both of these integers will be given in decimal.
Output
For each case of input you have to print the case number and the digit(s) of factorial n in the given base.
Sample Input
5
5 10
8 10
22 3
1000000 2
0 100
Sample Output
Case 1: 3
Case 2: 5
Case 3: 45
Case 4: 18488885
Case 5: 1
#include<cmath>
#include<algorithm>
#include<iostream>
#include<cstdio>
#include<cstring>
#define maxn 1000010
#define ll long long
using namespace std;
int t;
double a[maxn];
ll n,k;
double ans;
void init()
{
a[0]=log(1);
for(int i=1;i<maxn;i++)
a[i]=a[i-1]+log(i);
}
int main()
{
scanf("%d",&t);
init();
int w=0;
while(t--)
{w++;
ll n,k;
scanf("%lld%lld",&n,&k);
double ans=a[n]/log(k)+1;
int sum=(int)ans;
printf("Case %d: %d\n",w,sum);
}
return 0;
}