python/TangDou/XiTi/1384.cpp

#include <bits/stdc++.h>

using namespace std;
const int N = 100000;
struct Node {
    int pos;
    int step;
};

int main() {
    int n, k; //农夫位置，牛的位置
    cin >> n >> k;

    queue<Node> q;
    q.push({n, 0}); //农夫位置，步数

    while (q.size()) {
        auto t = q.front();
        q.pop();
        //出口
        if (t.pos == k) {
            cout << t.step << endl;
            break;
        }
        if (t.pos + 1 <= N) q.push({t.pos + 1, t.step + 1});
        if (t.pos - 1 >= 0) q.push({t.pos - 1, t.step + 1});
        if (t.pos <= t.pos * 2) q.push({t.pos * 2, t.step + 1});
    }

    return 0;
}