[c language] PTA 7-51 sum the first n terms of odd part sequence

This question requires the preparation of procedures , Calculation sequence 1 + 1/3 + 1/5 + ... Before N Sum of items .

Input format :

Input gives a positive integer on a line N.

Output format :

In a row, press “sum = S” The format of the output part and the value of S, Accurate to the decimal point 6 position . The calculation results should not exceed the double precision range .

sample input :

23

No blank lines at the end

sample output :

sum = 2.549541

No blank lines at the end

Be careful sum The type of is a real number . If i Integers , It cannot be written as 1/(2*i-1).

#include<stdio.h>
int main(){
	
	int N;
	double sum=0;
	double i;
	scanf("%d",&N);
	
	for(i=1;i<=N;i++){
		sum=sum+1.0/(2*i-1);
	}
	printf("sum = %.6f",sum);
	return 0;
}