uva-1388

刘汝佳书的代码：

#include<cstdio>#include<cmath>#include<iostream>using namespace std;int main(){int n,m;while(scanf("%d%d",&n,&m)!=EOF){double ans=0;for(int i=1;i<n;++i){double pos=(double)i/n*(n+m);ans+=fabs(pos-floor(pos+0.5))/(n+m);}printf("%.4lf\n",ans*10000);}return 0;}