解答：
#include <stdio.h>
#include <math.h>
int main() {
double down = 1; //分母从1开始
double result = 0;
double flag = 1;
for(; fabs(1/down) > pow(10,-6); down+=2) { //分母累加2
result += flag*(1/down); //分子始终为1
//printf("(%f)*(1/%f) = \n", flag, down);
//printf("result = %10.8f\n", 4*result);
flag *= -1;
}
printf("PI=%10.8f\n", 4*result);
return 0;
} #include <stdio.h>
#include <ma
