【C语言程序03】前n项求和

1.程序代码

#include
int main()
{
	int i;
	int n;
	double sum=0.0;
	scanf("%d", &n);
	for(i=1;i<=n;i++){
		sum += 1.0/i;
		}
	printf("f(%d) = %f n", n, sum);
	return 0;
}

2.运行结果

1.程序代码

#include
int main()
{
	int i;
	int n;
	double sum=0.0;
	double sign = 1.0;
	scanf("%d", &n);
	for(i=1;i<=n;i++){
		sum += sign/i;
		sign=-sign;
		}
	printf("f(%d) = %f n", n, sum);
	return 0;
}

2.运行结果

1.程序代码

#include
int main()
{
	int i;
	int n;
	double sum=0.0;
	double sign = 1.0;
	scanf("%d", &n);
	for(i=2;i<=n;i++){
		sum += sign/i;
		sign=-sign;
		}
		sum = sum + 1;
	printf("f(%d) = %f n", n, sum);
	return 0;
}

2.运行结果