CodeForces 13A - Numbers

主要还是理解题意！然后进制的转换！

#include <iostream>#include <cstdio>using namespace std;int gcd(int a,int b){  return b==0?a:gcd(b,a%b);}int main(){  int n;  cin>>n;  int sum=0;  for(int i=2;i<=n-1;++i)  {    int tmp=n;    while(tmp!=0)    {        sum+=(tmp%i);        tmp/=i;    }  }  int c=gcd(sum,n-2);  printf("%d/%d",sum/c,(n-2)/c);  return 0;}