python/TangDou/Bfs/1382.cpp

#include <bits/stdc++.h>

using namespace std;

struct Node {
    int number; //值
    int cnt;    //次数
};
const int N = 1e5 + 10;
bool st[N];
int main() {
    int a, b;
    cin >> a >> b;
    queue<Node> q;
    q.push({a, 0});
    st[a] = true;
    while (q.size()) {
        auto t = q.front();
        q.pop();
        if (t.number == b) {
            cout << t.cnt << endl;
            break;
        }
        if (!st[t.number + 1]) {
            st[t.number + 1] = true;
            q.push({t.number + 1, t.cnt + 1});
        }
        if (!st[t.number * 2]) {
            st[t.number * 2] = true;
            q.push({t.number * 2, t.cnt + 1});
        }
    }
    return 0;
}