LightOJ - 1234 Harmonic Number 欧拉公式求调和级数

#include <bits/stdc++.h>
using namespace std;
const double r = 0.5772156649015328606065;
double ans[10001];

int main()
{
	int t,n,cnt=1;
	for(int i=1;i<=10000;i++){
		ans[i] = ans[i-1] + 1/(double)i;
	}
	scanf("%d",&t);
	while(t--){
		scanf("%d",&n);
		if(n<=10000){
			printf("Case %d: %.10lf\n",cnt++,ans[n]);
		}else{
			printf("Case %d: %.10lf\n",cnt++,log((double)n)+r+1/(2*(double)n));
		}
	}
	
	return 0;
 }