1 #include <stdio.h>
2 #include <stdlib.h>
3 int main() 4 { 5
6 int t; 7 double r, s ,c; 8
9 do{ 10 printf ("請輸入一個圓的半徑值r: "); 11 scanf ("%lf", &r); 12 if (r >= 0) 13 { 14 s = 3.14 * r * r; 15 c = 2 * 3.14 * r; 16 printf("圓的面積s = %.2lf\n",s); 17 printf("圓的周長c = %.2lf\n",c); 18 } 19 else
20 printf("您輸入的半徑確定大於等於0嗎？\n"); 21 printf("您需要再輸入一次r值嗎？\n"); 22 printf("Yes --- 按數字鍵【1】\n"); 23 printf("No --- 按數字鍵【0】\n"); 24 scanf ("%d",&t); 25
26 } while ( t == 1 ); 27
28 return 0; 29 }