240115 올바른 괄호의 갯수

private int count;

public int solution(int n) {
	count = 0;
	dfs(0, 0, n);
	return count;
}

public void dfs(int left, int right, int n) {
	if (left > n || right > n || left < right) {
		return;
	}

	if (left == n && right == n) {
		count++;
		return;
	}

	dfs(left + 1, right, n);
	dfs(left, right + 1, n);
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/12929