UVa 11678 - Card's Exchange (actually just an array manipulation problem)

Link:https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=78&page=show_problem&problem=2725
Sol:

#include <cstdio>
	#include <map>
	using namespace std;
	int main()
	{
	map<int, bool> cards;
	int aCards, bCards, current, aCount, bCount;
	while (scanf("%d %d", &aCards, &bCards), aCards && bCards)
	{
	aCount = bCount = 0;
	cards.clear();
	for (int i = 0; i < aCards; ++i)
	{
	scanf("%d", &current);
	if (cards.find(current) == cards.end())
	{
	++aCount;
	cards[current] = true;
	}
	}
	for (int i = 0; i < bCards; ++i)
	{
	scanf("%d", &current);
	map<int, bool>::iterator iter = cards.find(current);
	if (iter == cards.end())
	{
	cards[current] = false;
	++bCount;
	}
	else if (iter->second)
	{
	iter->second = false;
	--aCount;
	}
	}
	printf("%d\n", aCount < bCount ? aCount : bCount);
	}
	}