p25：預(yù)處理器命令

#include <stdio.h>

#define MAX(a,b) (a>b)? a:b //在帶參宏定義中，形式參數(shù)不分配內(nèi)存單元，因此不必做類型定義

#define PI 3.14159265

#define ARRAY_SIZE 1000

#define G 9.8

#define S(a,b) a * b

#define S(r) PI * r * r

#define CIRCLE(r,L,S,V) L = 2 * PI * r; S = PI * r * r; V = 4.0 / 3 * PI * r * r * r

#define LETTER

int main(void)

{

//int myArray[ARRAY_SIZE];

char str[20] = "C Language";

char c;

int i = 0;

while ((c = str[i]) != '\0')

{

i++;

#ifdef LETTER

if (c >= 'a' && c <= 'z')

{

c = c - 32;

}

#else

if (c >= 'A' && c <= 'Z')

{

c = c + 32;

}

#endif//

????

printf("%c",c);

}

printf("\n");

return 0;

//int x,y,max;

//

//printf("input two numbers:");

//scanf_s(" % d % d",&x ,&y);

//max = MAX(x,y);

//printf("max = %d\n",max);

}