bfs问题
同类型的有845八数码、3156卡牌换位

#include <cstdio>
#include <iostream>
#include <cstring>
#include <algorithm>
#include <queue>
#include <unordered_map>

using namespace std;

string start,endss;
int len;

int bfs(){
    queue<string> Q;
    Q.push(start);
    unordered_map <string,int>dist;
    dist[start] = 0;

    while(!Q.empty()){
        auto t = Q.front();
        Q.pop();

        int distance = dist[t];
        if(t == endss){
            return distance;
        }

        int dx[6] = {1,-1,2,-2,3,-3};

        //开始移动；
        int pos = t.find('*');
        for(int i = 0;i < 6;i++){
            int nx = pos + dx[i];
            if(nx >= 0 && nx < len){
                swap(t[pos],t[nx]);
                if(dist.count(t) == 0){
                    dist[t] = distance + 1;
                    Q.push(t);
                }
                swap(t[pos],t[nx]);
            }
        }
    }
    return -1;
}

int main(){

    getline(cin,start);
    getline(cin,endss);
    len = start.length();

    cout << bfs() << endl;

    return 0;
}