[OpenJudge-NOI]求小数的某一位

代码

#include <cstdio>#include <iostream>#include <cstring>using namespace std;int Gcd(int a,int b) {    return b==0?a:Gcd(b,a%b);}int a,b,n,ans;int main() {    cin>>a>>b>>n;    int t=Gcd(a,b);    a/=t;b/=t;    for(int i=1;i<=n;i++){        a*=10;        ans=a/b;        a%=b;    }    cout<<ans;}