USACO3.25Magic Squares（bfs）

 /*
     ID: shangca2
     LANG: C++
     TASK: msquare
  */
 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<stdlib.h>
 #include<queue>
 #define INF 0xfffffff
 using namespace std;
 int o[];
 typedef struct node
 {
     int num;
     int a[],pre;
     char c;
 }st;
 st q[],ss;
 char s1[],s2[];
 int f[][][][][][][];
 void bfs()
 {
     int i,d=,p=,minz = INF;
     q[d].num = ;
     q[d].pre = -;
     for(i = ; i <=  ; i++)
     q[d].a[i] = i;
     f[][][][][][][] = ;
     while(p!=d)
     {
         p++;
         ss = q[p];
         if(ss.num>minz)
         continue;
         for(i = ; i <=  ; i++)
         {
             if(ss.a[i]!=o[i])
             break;
         }
         if(i==)
         {
             int x = ss.pre,w=;
             s2[w++] = ss.c;
             while(x!=-)
             {
                 s2[w++] = q[x].c;
                 x = q[x].pre;
             }
             s2[w] = '\0';
             if(ss.num<minz)
             {
                 minz = ss.num;
                 strcpy(s1,s2);
             }
             else
             {
                 if(strcmp(s2,s1)>)
                 strcpy(s1,s2);
             }
             continue;
         }
         int b[];
         for(i = ; i >=  ; i--)
             b[i] = ss.a[-i+];
         if(!f[b[]-][b[]-][b[]-][b[]-][b[]-][b[]-][b[]-])
         {
             d++;
             q[d].num = ss.num+;
             q[d].c = 'A';
             q[d].pre = p;
             f[b[]-][b[]-][b[]-][b[]-][b[]-][b[]-][b[]-] = ;
             for(i = ; i <=  ; i++)
             q[d].a[i] = b[i];
         }
         for(i = ; i <=  ; i++)
         {
             if(i>&&i<=)
             b[i] = ss.a[i-];
             if(i==)
             b[i] = ss.a[];
             if(i==)
             b[i] = ss.a[];
             if(i>&&i<)
             b[i] = ss.a[i+];
         }
         if(!f[b[]-][b[]-][b[]-][b[]-][b[]-][b[]-][b[]-])
         {
             d++;
             q[d].num = ss.num+;
             q[d].c = 'B';
             q[d].pre = p;
             f[b[]-][b[]-][b[]-][b[]-][b[]-][b[]-][b[]-] = ;
             for(i = ; i <=  ; i++)
             q[d].a[i] = b[i];
         }
         for(i = ; i <=  ; i++)
         {
             if(i==)
             b[i] = ss.a[];
             else if(i==)
             b[i] = ss.a[];
             else if(i==)
             b[i] = ss.a[];
             else if(i==)
             b[i] = ss.a[];
             else b[i] = ss.a[i];
         }
         if(!f[b[]-][b[]-][b[]-][b[]-][b[]-][b[]-][b[]-])
         {
             d++;
             q[d].num = ss.num+;
             q[d].c = 'C';
             q[d].pre = p;
             f[b[]-][b[]-][b[]-][b[]-][b[]-][b[]-][b[]-] = ;
             for(i = ; i <=  ; i++)
             q[d].a[i] = b[i];
         }
     }
     printf("%d\n",minz);
     if(minz!=)
     {
         int k = strlen(s1),qq=;
         for(i = k- ; i>= ; i--)
         {
             qq++;
             cout<<s1[i];
             if(qq%==||i==)
             puts("");
         }
     }
     else
     puts("");
 }
 int main()
 {
     freopen("msquare.in","r",stdin);
     freopen("msquare.out","w",stdout);
     int i;
     for(i =; i <=  ; i++)
     cin>>o[i];
     bfs();
     return ;
 }

这题 亮点在于开了个7维数组。。。