~cpp 
#include <stdio.h>

int search_middleNum(int *, int *, int *);
void changeXY(int *, int *);
void main()
{
	int a, b, c, middleNum;
	while(1){
		printf("멈추려면 '-999 0 0' 입력\n");
		printf("비교할 A, B, C 값을 차례로 입력 : ");
		scanf("%d %d %d", &a, &b, &c);
		if(a == -999){
			break;
		}
		middleNum = search_middleNum(&a, &b, &c);
		printf("중위수 = %d", middleNum);
	}
}

int search_middleNum(int *a, int *b, int *c)
{
	int middle;
	if(*a >= *b){changeXY(a, b);};
	if(*a >= *c){changeXY(a, c);};
	if(*b >= *c){changeXY(b, c);};
	middle = *b;
	return middle;
}

void changeXY(int *x, int *y)
{
	int temp;
	temp = *x;
	*x = *y;
	*y = temp;
}