1.#include<stdio.h>
#include<math.h>
void main()
{
int i=0,j=1,n,k;
float m,sum=0,z;
do
{
i++;
k=pow(-1,i+1);
m=1*1.0/j;
sum=m*k+sum;
j+=2;
if(fabs(m)<=1e-6)//zhe ge tui chu tiaojian ni ziji panduan xia
{
break;
}
}while(1);
z=4*sum;
printf("z=%10.6f\n",z);
}
//公式:(1-1/3+1/5+1/7........)*4=pi
2.#include<stdio.h>
#include<math.h>
void main()
{
int i=0,j=1,n,k;
float m,sum=0,z;
do
{
i++;
k=pow(-1,i+1);
m=1*1.0/j;
sum=m*k+sum;
j+=2;
}while(fabs(m)>=1e-6);
z=4*sum;
printf("z=%10.6f\n",z);
}
//公式:(1-1/3+1/5+1/7........)*4=pi