백준 3009 c++

#include <iostream>

using namespace std;

int input(int lower, int upper);
void square_input(int square[][2]);
void print_forth_dot(int square[][2]);


int main(void)
{
	int square[3][2] = {};

	square_input(square);
	print_forth_dot(square);

	return 0;
}

void square_input(int square[][2])
{
	int i;
	for (i = 0; i < 3; i++)
	{
		square[i][0] = input(1, 1000);
		square[i][1] = input(1, 1000);
	}

	return;
}

int input(int lower, int upper)
{
	int A;

	while (1)
	{
		cin >> A;
		if (A >= lower && A <= 10000000)
		{
			break;
		}
		else
		{
			;
		}
	}

	return A;
}

void print_forth_dot(int square[][2])
{
	int i;
	int x, y;
	if (square[0][0] == square[1][0])
	{
		x = square[2][0];
	}
	else if(square[0][0] == square[2][0])
	{
		x = square[1][0];
	}
	else
	{
		x = square[0][0];
	}

	if (square[0][1] == square[1][1])
	{
		y = square[2][1];
	}
	else if (square[0][1] == square[2][1])
	{
		y = square[1][1];
	}
	else
	{
		y = square[0][1];
	}
	cout << x << " " << y << endl;

	return;
}