46.md

题目：宏#define命令练习。

#include<stdio.h>
#define TRUE 1
#define FALSE 0
#define SQ(x) (x)*(x)

int main()
{
	int num;
	int flag = 1;
	//num < 20 程序将终止
	while (flag)
	{
		scanf("%d", &num);
		printf("该数的平方为 %d \n", SQ(num));
		if (num >= 20)
			flag = TRUE;
		else
			flag = FALSE;
	}

	return 0;
}