Codeforces Round #614 (Div. 2)B（JOE is on TV!）

B - JOE is on TV!

题目链接：http://codeforces.com/contest/1293/problem/B

思路：这题没咋看题，，，直接看了底下注释说是1/2+1/1，再看了两个样例，把数据往调和函数里一代就对了，，，直接暴力for循环求就行了

// 
// Created by HJYL on 2020/1/13.
//
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<queue>
#include<cmath>
#define eps 1e-8
#define Inf 0x7fffffff
//#include<bits/stdc++.h>
using namespace std;
const int maxn=1e5+100;
struct Point{
    double x,y;
};
double min(double a, double b) { return a < b ? a : b; }

double max(double a, double b) { return a > b ? a : b; }

bool IsSegmentIntersect(Point a, Point b, Point c, Point d)
{
    if( min(a.x, b.x) > max(c.x, d.x) ||
        min(a.y, b.y) > max(c.y, d.y) ||
        min(c.x, d.x) > max(a.x, b.x) ||
        min(c.y, d.y) > max(a.y, b.y) )
        return 0;

    double h, i, j, k;

    h = (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x);
    i = (b.x - a.x) * (d.y - a.y) - (b.y - a.y) * (d.x - a.x);
    j = (d.x - c.x) * (a.y - c.y) - (d.y - c.y) * (a.x - c.x);
    k = (d.x - c.x) * (b.y - c.y) - (d.y - c.y) * (b.x - c.x);

    return h * i <= eps && j * k <= eps;
}

int main()
{
    int T;
    scanf("%d",&T);
    if(T==1)
        printf("1.000000000000\n");
    else
    {
        double sum=0.0;
        for(int i=1;i<=T;i++)
        {
            sum+=(1.0)/(i*1.0);
        }
        printf("%.12lf\n",sum);
    }
    return 0;
}