Shuffle'm Up (map ? BFS)

 1 #include <iostream>
 2 #include <string>
 3 #include <cstring>
 4 #include <queue>
 5 #include <string.h>
 6 #include <stdio.h>
 7 #include <map>
 8 
 9 using namespace std;
10 
11 const int maxn = 1005;
12 
13 map<string,int> d;
14 typedef struct Node{
15     string val;
16     int cnt;
17 }Node;
18 
19 int n;
20 int T;
21 string s1,s2,es,str;
22 
23 
24 int bfs()
25 {
26    queue<Node> q;
27    Node node;
28    for (int i=0;i<s1.length();i++)
29    {
30        str += s2[i];
31        str += s1[i];
32    }
33    node.val = str;
34    node.cnt = 1;
35    d[str] = 1;
36    q.push(node);
37    while (!q.empty())
38    {
39        Node cur = q.front();
40        q.pop();
41        if (cur.val == es)
42        {
43            return cur.cnt;
44        }
45        s1 = cur.val.substr(0,n);
46        s2 = cur.val.substr(n,n);
47        str = "";
48        for (int i=0;i<s1.length();i++)
49        {
50            str += s2[i];
51            str += s1[i];
52        }
53        cur.val = str;
54        if (d[cur.val])
55            return -1;
56        d[str] = 1;
57        cur.cnt++;
58        q.push(cur);
59    }
60 }
61 
62 
63 int main()
64 {
65     cin >> T;
66     int t = 1;
67     while (T--)
68     {
69         str = "";
70         cin >> n;
71         cin >> s1;
72         cin >> s2;
73         cin >> es;
74         int ant = bfs();
75         printf("%d ",t++);
76         printf("%d\n",ant);
77     }
78     return 0;
79 }