#include <stdio.h>#include <math.h>
int main(){
double c=1.0,d,y=1.0; while(fabs(y)>=1e-8) { c=c+2; d=-1/c; y=y+d; } printf("%lf\n",y); return 0;
}
到不了那么小,改下:while(fabs(y)>1e-1)