NEFU 119
和上一题一样,注意除不尽为0
#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> using namespace std; long long n,p; int main(){ int t; scanf("%d",&t); while(t--){ scanf("%lld%lld",&n,&p); int a,b; a=b=0; for(long long i=p;i<=n*2;i*=p) a+=((2*n)/i); for(long long i=p;i<=n;i*=p) b+=(n/i); long long tmp=a-b-b; printf("%lld\n",tmp>0?tmp:0); } return 0; }