bj_13549.cpp

#include <iostream> 
#include <algorithm> 
#include <utility> 
#include <map> 
#include <stack> 
#include <queue> 
#include <string.h> 
#include <cstdlib>
#include <vector> 
#include <math.h>

using namespace std;


int N, K;
int dp[200002] = {};
bool visit[200002] = {};

void BFS() {
    queue<int> Q; 
    Q.push(N);
    visit[N] = true;

    while(!Q.empty()) {
        int x = Q.front();
        Q.pop();

        int arr[3] = {
            2*x, x-1, x+1
        };

        for(int i = 0; i<3; i++) {
            if(visit[arr[i]] == false && arr[i] >= 0 && arr[i] <= 100000) {
                dp[arr[i]] = dp[x] + 1;
                if(i == 0) 
                    dp[arr[i]] = dp[x];

                visit[arr[i]] = true;
                Q.push(arr[i]);   
            }
        }
    }
}


int main() {
    cin.tie(NULL);
    cout.tie(NULL);
    ios_base::sync_with_stdio(false);
    cin >> N >> K;  

    memset(visit, false, sizeof(visit));
    BFS();
    cout << dp[K];

}