原文

作者：
huolong , 时间：2022-01-02 11:25:17 , 所有人可见, 阅读 19
```cpp
#include 
#include 
#include 
#include 

using namespace std;

int bfs(string state)
{
    queue q;
    unordered_map d;

    __________
    d[state] = 0;

    int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};

    string end = "12345678x";
    while (q.size())
    {
        auto t = q.front();
        q.pop();

        __________

        int distance = d[t];
        int k = t.find('x');
        int x = __________, y =__________;
        for (int i = 0; i < 4; i ++ )
        {
            int a = x + dx[i], b = y + dy[i];
            if (a >= 0 && a < 3 && b >= 0 && b < 3)
            {
                __________;
                if (!d.count(t))
                {
                    __________;
                    q.push(t);
                }
                swap(t[a * 3 + b], t[k]);
            }
        }
    }

    return -1;
}

int main()
{
    string state;
	char c;
    for (int i = 0; i < 9; i ++ )
    {
        cin >> s;
        state += c;
    }

    cout << bfs(state) << endl;

    return 0;
}

```

                                
                            