[C++知识库]C语言计算1/1-1/2+1/3-1/4......1+1/99-1/100

对于我这种初学者比较容易理解的两种方法

第一种是先计算正数的和，然后计算负数的和，最后加在一起。

#define _CRT_SECURE_NO_WARNINGS 1
#include  <stdio.h>
int main()
{
	float a, b;
	float c = 0 ; 
	float d = 0;
	for (b = 1; b < 100; b = b + 4)//计算正分数的和
	{
		a = b + 2;
		float  num = 1 / b + 1 / a;
		c = c + num;
	}
		printf("正数的和：%f\n", c);

	for (b = 2; b <= 100; b += 4)//计算负数的和
	{
		a = b + 2;
		float  num = - 1 / b - 1 / a;
		d = d + num;
	}
		printf("负数的和：%f\n", d);
	
	float mun = d + c;
	printf("总和：%f\n", mun);
	return 0;
}

第二种方法是直接计算总和

#define _CRT_SECURE_NO_WARNINGS 1
#include  <stdio.h>
float  Add(float x, float y)
{
	float  z = 0;
	z = 1 / x - 1 / y;
	return z;
}
int main()
{
	float a ;
	float b ;
	float c = 0;
	float s = 0;
	for (a = 1; a <= 100; a += 2)
	{
		b = a + 1;
	    float sum = Add(a, b);
	    s = s + sum;
    }
		printf("%f\n", s);
	return 0;
}