usaco 3.2 Magic Squares

/*
ID:rayafjy1
PROG:msquare
LANG:C++
*/
#include <iostream>
#include <stdio.h>
#include <string.h>

using namespace std;

struct node{
    short int a[8], c;
    int step, pre;
} q[40321];
int s, e;
short int start[8], end[8];
bool vis[8][8][8][8][8][8][8];

void input() {
    int i, x;
    for (i = 0; i < 8; i++) start[i] = i;
    for (i = 0; i < 8; i++) {
        scanf("%d", &x);
        end[i] = x - 1;
    }
}

bool check(short int a[]) {
    for (int i = 0; i < 8; i++) if (a[i] != end[i]) return 0;
    return 1;
}

void solve1 (short int a[]) {
    for (int i = 0; i < 4; i++) swap(a[i], a[7 - i]);
}

void solve2 (short int a[]) {
    short int i, tmp;
    tmp = a[3];
    for (i = 2; i >= 0; i--) a[i + 1] = a[i];
    a[0] = tmp;
    tmp = a[4];
    for (i = 5; i <= 7; i++) a[i - 1] = a[i];
    a[7] = tmp;
}

void solve3 (short int a[]) {
    short int tmp = a[1];
    a[1] = a[6];
    a[6] = a[5];
    a[5] = a[2];
    a[2] = tmp;
}

void biaoji(node n1) {
    vis[n1.a[0]][n1.a[1]][n1.a[2]][n1.a[3]][n1.a[4]][n1.a[5]][n1.a[6]] = 1;
}

bool ok(node n1) {
    if (vis[n1.a[0]][n1.a[1]][n1.a[2]][n1.a[3]][n1.a[4]][n1.a[5]][n1.a[6]] == 0) return 1;
    return 0;
}

void print(short int a[]) {
    for (int i = 0; i < 4; i++) cout << a[i] << ' ';
    cout << endl;
    for (int i = 7; i >= 4; i--) cout << a[i] << ' ';
    cout << endl;
    cout << endl;
}


void bfs() {
    node n1;
    memcpy(n1.a, start, sizeof(start));
    n1.step = 0;
    n1.pre = -1;
    n1.c = -1;
    biaoji(n1);
    q[0] = n1;
    s = 0;
    e = 1;
    if (check(n1.a)) return;
    while (s < e) {
        node n2 = q[s++];
        for (int i = 0; i < 3; i++) {
            node n3 = n2;
            n3.pre = s - 1;
            n3.step++;
            n3.c = i;
            if (i == 0) solve1(n3.a);
            else if (i == 1) solve2(n3.a);
            else if (i == 2) solve3(n3.a);
            if (ok(n3)) {
                biaoji(n3);
                q[e++] = n3;
                if (check(n3.a)) return;
            }
        }
    }
}

char output[40321];
int l;

void dosolve() {
    memset(vis, 0, sizeof(vis));
    bfs();
    l = 0;
    printf("%d\n", q[--e].step);
    while (q[e].pre != -1) {output[l++] = q[e].c + 'A'; e = q[e].pre;}
    int i;
    for (i = l - 1; i >= 0; i--) {
        printf("%c", output[i]);
        if ((l - i) % 60 == 0 || i == 0) printf("\n");
    }
    if (l == 0) printf("\n");
}

int main() {
    freopen("msquare.in", "r", stdin);
    freopen("msquare.out", "w", stdout);
    input();
    dosolve();
    return 0;
}