zzulioj 1040: Summation of sequence 1

Title description
Input an integer n, and output the number sequence 1+1/3+1/5+...the sum of the first n items.
Input
There is only one positive integer n.
Output The
result retains 2 decimal places, and it occupies a separate line.
Sample input Copy
3
Sample output Copy
1.53

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

for:

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