求编写一个程序,在屏幕上输出一个由*组成的空心圆
求编写一个程序,在屏幕上输出一个由*组成的空心圆

#include "stdio.h" #include "math.h" main() { int R=10; int i,j; for(i=0;i<=2*R;i++) { for(j=0;j<=2*R;j++) { if(j==ceil(R-sqrt(R*R-(i-R)*(i-R)))||j==ceil(R+sqrt(R*R-(i-R)*(i-R)))) { printf("%2s","*"); } else { printf("%2s"," "); } } printf("\n"); } }