public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer tokenizer = new StringTokenizer(br.readLine());
int n = Integer.parseInt(tokenizer.nextToken());
int k = Integer.parseInt(tokenizer.nextToken());
System.out.println(dfs(n, k));
}
private static int dfs(int n, int k) {
if (n >= k)
return n - k;
if (k == 1)
return 1;
if (k % 2 == 0)
return Math.min(k - n, dfs(n, k / 2) + 1);
return Math.min(dfs(n, k + 1), dfs(n, k - 1)) + 1;
}
출처:https://www.acmicpc.net/problem/1697
