USACO3.2.5 Magic Squares (msquare)

/*
ID:shijiey1
PROG:msquare
LANG:C++
*/
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <string>
#include <iostream>
#include <queue>
#include <map>

using namespace std;

struct Node {
int deep;
string stat, trans;
Node() {
stat = "        ";
trans = "";
}
};

string start = "12345678";
string end = "";
queue<Node> q;
map<string, int> done;
int main() {
freopen("msquare.in", "r", stdin);
freopen("msquare.out", "w", stdout);
int t;
for (int i = 0; i < 8; i++) {
scanf("%d", &t);
end += t + '0';
}
Node node;
node.stat = start;
node.trans = "";
node.deep = 0;
q.push(node);
done[start] = 1;
while (!q.empty()) {
Node now = q.front();
q.pop();
if (now.stat == end) {
cout << now.deep << endl << now.trans << endl;
break;
}
Node next = Node();
next.deep = now.deep + 1;

next.trans = now.trans + 'A';
for (int i = 0; i < 4; i++) {
next.stat[i] = now.stat[7 - i];
next.stat[7 - i] = now.stat[i];
}
if (!done[next.stat]) {
q.push(next);
done[next.stat] = 1;
}
next.trans = now.trans + 'B';
for (int i = 0; i < 4; i++) {
next.stat[i] = now.stat[(i + 3) % 4];
next.stat[i + 4] = now.stat[(i + 5) % 4 + 4];
}
if (!done[next.stat]) {
q.push(next);
done[next.stat] = 1;
}
next.trans = now.trans + 'C';
next.stat[0] = now.stat[0];
next.stat[3] = now.stat[3];
next.stat[4] = now.stat[4];
next.stat[7] = now.stat[7];
next.stat[1] = now.stat[6];
next.stat[2] = now.stat[1];
next.stat[5] = now.stat[2];
next.stat[6] = now.stat[5];
if (!done[next.stat]) {
q.push(next);
done[next.stat] = 1;
}
}

return 0;
}