240601 숨바꼭질 3

private static int min = Integer.MAX_VALUE;

public static void main(String[] args) throws IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	StringTokenizer st = new StringTokenizer(br.readLine());

	int n = Integer.parseInt(st.nextToken());
	int k = Integer.parseInt(st.nextToken());

	if (n == 0) {
		dfs(1, k, 1);
	} else {
		dfs(n, k, 0);
	}
	System.out.println(min);
}

private static void dfs(int n, int k, int count) {
	if (n >= k) {
		min = Math.min(min, count + n - k);
		return;
	}
	min = Math.min(min, count + k - n);
	
	if (k % 2 == 0) {
		dfs(n, k / 2, count);
	} else {
		dfs(n, k + 1, count + 1);
		dfs(n, k - 1, count + 1);
	}
}

출처:https://www.acmicpc.net/problem/13549