20140711 loop

又是一道名为loop的题.......

首先我想的是(n-1)/2 然后就信心满满地交了上去.....之后就是WAWAWAWAWAWAWA......>

后来经过指点，才知道应该是1+1/2+1/3+1/4+1/5+.......1/n=

#include<iostream>
#include<cmath>
#include<cstdio>
#include<cstdlib>
 
using namespace std;
 
const double euler=0.57721566490;
 
long long n;
int m;

int main() {
    freopen("loop.in","r",stdin);
    freopen("loop.out","w",stdout);
    scanf("%I64d%d",&n,&m);
    if(n<5000000) {
        double ans=0.0;
        for(int i=1;i<=n;i++)
            ans+=(1.0/i);
        printf("%d
",(int)floor(ans*m - (1e-8)));
    } else {
        printf("%d
",(int)floor((log(n)+euler)*m - (1e-8)));
    }
    return 0;
}