2020-12-15

pi的近似值计算

#include<stdio.h>
#include<math.h>
int main(void)
{
	double pi, sum = 0, term, sign = 1.0;
	int count = 0, n = 1;
	do 
	{
		term = sign / n ;
		sum = sum+term ;
		count++;
		sign = -sign ;
		n = n + 2 ;
	} while( fabs(term) >= 1e-4);
	pi = sum * 4 ;
	printf("pi = %f\ncount = %d \n",pi,count) ;
	return 0;
}

e的近似值计算

#include<stdio.h>
#include<math.h>
int main(void)
{
	int n=1,count=1; 
	double sum=1,term=1; 
	while(fabs(term)>=1e-5) 
	{ 
		term=term*(1.0/n); 
		sum=sum+term; 
		n++; 
		count++; 
	} 
	printf("sum=%f,count=%d\n",sum,count); 

	return 0;
}