C :

#include <stdio.h>
int main()
{int k,n=0;
double Sn=0;//这道题的关键在于定义Sn为double，如果是float只过60%的数据
scanf("%d",&k);
while(Sn<=k)
{n++;
Sn+=1.0/n;//注意分子或分母必须有小数点
} 
printf("%d",n);
}

C++ :

#include<stdio.h>
int main()
{
 int n=1,k;
 double s=0.0;
 scanf("%d",&k);
 while(s<k)
 {
	 s+=1/double(n);
	 n++;
 }
 printf("%d\n",n-1);
 return 0;
}

Pascal :

var k,n:longint;s:real;
begin
 readln(k);
 while s<=k do
  begin
   inc(n);
   s:=s+1/n;
  end;
 writeln(n);
end.

Java :

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner input=new Scanner (System.in);
		int k=input.nextInt();
		double a=0;
		int i=0;
		while(a>=0){
			a+=(double)1/(i+1);
			i++;
			if(a>k) {
				System.out.println(i);
				a=-1;
			}
			}
		}
	}

C# :

using System;

namespace _20927
{
    class Class1
    {
        static void Main()
        {
            int k = Convert.ToInt16(Console.ReadLine());
            double n=2, sn=1;
            while (sn < k)
            {
                sn += 1 / n++;                
            }
            if(sn!=k)n--;
            Console.WriteLine(n);
            Console.ReadLine();
        }
    }
}