#include
    
     #include
     
      int main(){	int i,n,s;	double k,y2;	printf("输入切割次数：");	scanf("%d",&n);	i=0;//切割次数 	k=3.0;//初始值 	y2=1.0;//内接六边形的边长 	s=6;//初始内接多边形的边数 	while(i<=n){		printf("%d次切割 %d条边PI=%.24f\n",i,s,k*sqrt(y2));		s*=2;//边数增加一倍 		y2=2-sqrt(4-y2);//弦长 		i++;		k*=2.0;	}		return 0;}