POJ-2965-The Pilots Brothers' refrigerator

#include<cstdio>
#include<cstring>
#include<iostream>
#include<queue>
#include<string>
const int MAX=(1<<16)+1;
const int res=(1<<16)-1;
using namespace std;
bool vis[MAX];
int movex[MAX],movey[MAX];
struct node
{
int num;
int ans;
int x,y;
int pre;
}q[MAX];
int main()
{
char str[4][4];
while(scanf("%s",&str[0])!=EOF)
{
for(int i=1;i<4;i++)
scanf("%s",str[i]);
memset(vis,0,sizeof(vis));
node ita;
ita.num=0;
ita.ans=0;
for(int i=0;i<4;i++)
for(int j=0;j<4;j++)
if(str[i][j]=='-')
ita.num+=(1<<(i*4+j));
if(ita.num==res)
{
printf("0\n");
continue;
}
int last=1,pre=0;
q[0]=ita;
vis[ita.num]=1;
int ans=-1;
while(pre<last)
{
ita=q[pre++];
for(int i=0;i<16;i++)
{
node itb=ita;
itb.num=(itb.num^(1<<i));
for(int j=i%4;j<16;j+=4)
itb.num=(itb.num^(1<<j));
int itc=i/4*4;
for(int j=itc;j<itc+4;j++)
itb.num=(itb.num^(1<<j));
if(vis[itb.num])
continue;
itb.ans=ita.ans+1;
itb.x=i/4+1;
itb.y=i%4+1;
itb.pre=pre-1;
if(itb.num==res)
{
int cou=0,p=itb.pre;
printf("%d\n",ita.ans+1);
movex[cou]=itb.x;
movey[cou++]=itb.y;
for(int j=0;j<ita.ans;j++)
{
movex[cou]=q[p].x;
movey[cou++]=q[p].y;
p=q[p].pre;
}
for(int j=cou-1;j>=0;j--)
printf("%d %d\n",movex[j],movey[j]);
ans=1;
break;
}
itb.ans=ita.ans+1;
itb.x=i/4+1;
itb.y=i%4+1;
itb.pre=pre-1;
q[last++]=itb;
vis[itb.num]=1;
}
if(ans!=-1)
break;
}
}
return 0;
}