UVa 10422 Knights in FEN

题目：http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1363

#include<cstdio>
#include<cstring>
#include<queue>
#include<set>
using namespace std;

struct State
{
	short step,x,y;
	char map[5][5];
};
struct cmp
{
	bool operator () (State a,State b) const
	{
		return memcmp(a.map,b.map,25)<0;
	}
};

char final[5][5]={'1','1','1','1','1','0','1','1','1','1','0','0',' ','1','1','0','0','0','0','1','0','0','0','0','0'};
set<State,cmp> vis;

int try_to_insert(State s)
{
	if(vis.count(s)) return 0;
	vis.insert(s);
	return 1;
}
void solve(State &head)
{
	if(memcmp(head.map,final,sizeof(final))==0)
	{
		printf("Solvable in 0 move(s).\n");
		return;
	}
	queue<State> q;
	q.push(head);
	while(!q.empty())
	{
		int i;
		short dir[8][2]={-1,-2,1,-2,-2,-1,2,-1,-1,2,1,2,-2,1,2,1};
		State cur;
		cur=q.front();
		q.pop();
		if(cur.step>=11)
		{
			printf("Unsolvable in less than 11 move(s).\n");
			return;
		}
		if(memcmp(cur.map,final,sizeof(final))==0)
		{
			printf("Solvable in %d move(s).\n",cur.step);
			return;
		}
		for(i=0;i<8;i++)
		{
			State next=cur;
			next.x=cur.x+dir[i][0];
			next.y=cur.y+dir[i][1];
			if(next.x<0||next.x>4||next.y<0||next.y>5) continue;
			char t=next.map[next.x][next.y];
			next.map[next.x][next.y]=next.map[cur.x][cur.y];
			next.map[cur.x][cur.y]=t;
			next.step++;
			if(try_to_insert(next))
				q.push(next);
		}
	}
}
int main()
{
	//freopen("in.txt","r",stdin);
	int i,j,N;
	State head;
	scanf("%d",&N);
	getchar();
	while(N--)
	{
		for(i=0;i<5;i++)
		{
			for(j=0;j<5;j++)
			{
				head.map[i][j]=getchar();
				if(head.map[i][j]==' ')
				{
					head.x=i;
					head.y=j;
				}
			}
			getchar();
		}
		head.step=0;
		vis.clear();
		solve(head);		
	}
	return 0;
}