一、N-S流程图；

二、运行结果；

三、源代码；

# define _CRT_SECURE_NO_WARNINGS
# include <stdio.h>
# include <math.h>

int main()
{
	//初始化变量值；
	int symbol = 1;
	double denominator = 1.0, sum = 0, term = 1.0;

	//循环判断；
	while (fabs(term) >= 1e-6)
	{
		//运算；
		sum = sum + term;

		//改变变量的值；
		symbol = -symbol;
		denominator = denominator + 2;
		term = symbol / denominator;
	}

	//运算；
	sum = sum * 4;

	//输出结果；
	printf("π的近似值为：%10.8f\n", sum);

	return 0;
}