#include <stdio.h>

//#define PI 3.14159//定義π

#define MULTI(x) (x*x)

int main(int argc, const char * argv[]) {
    // insert code here...
    /*
    int r1 = 3, r2 = 8;
    
    double s = PI * r1 * r1;//定義π  求圓的面積
    double s1 = PI * r2 * r2;
    
    printf("s = %.2f\n",s);
    printf("s1 = %.2f\n",s1);
     */
    
    int a = MULTI (10);
    
    printf("a = %d\n",a);
    
    //先替換  后計算
    int b = MULTI(11+11);//11+ 11*11 +11
    
    printf("b = %d\n",b);
    
    
#if defined (PI)//如果定義了PI，就編譯下面的代碼
    
    printf("。。。\n");
    #endif
    
    
    
#if !defined (PI)
    
    printf("^^^\n");
#endif
    return 0;
}