Determining the value of ln2 using loop-C++

 

#include<bits/stdc++.h>

using namespace std;

int main()
{
	double n,i;
	cin>>n;
	double sum1=0,sum2=0;
	for(i=1;i<=n;i+=2)
	 {
	  sum1+=1/i;
	 }
	for(i=2;i<=n;i+=2)
	 {
	  sum2+=1/i;
	 }
	 
	 cout<<sum1-sum2<<endl;

return 0;
}