走出迷宫

/* 迷宫求解
6
#s####
#O####
#O####
#O####
#OOOOt
######
10
##########
#sO#OOO#O#
#OO#OOO#O#
#OOOO##OO#
#O###OOOO#
#OOO#OOOO#
#O#OOO#OO#
#O###O##O#
##OOOOOOt#
##########

*/

#include <iostream>
#include <stack>
using namespace std;
#define  MAX 1000
struct Node
{
int x, y;
}tmp, s, t, order[MAX];
char Graph[MAX][MAX];

int IsFind(int x, int y)
{
if (x==t.x && y==t.y)
return 1;
return 0;
}
int Judge(stack<struct Node> &sta) //判断是否到达t
{
if (IsFind(tmp.x+1, tmp.y))
{
tmp.x = tmp.x + 1;
sta.push(tmp);
return 1;
}
else if (IsFind(tmp.x-1, tmp.y))
{
tmp.x = tmp.x - 1;
sta.push(tmp);
return 1;
}
else if (IsFind(tmp.x, tmp.y+1))
{
tmp.y = tmp.y + 1;
sta.push(tmp);
return 1;
}
else if (IsFind(tmp.x, tmp.y-1))
{
tmp.y = tmp.y - 1;
sta.push(tmp);
return 1;
}
return 0;
}
void Advance(stack<struct Node> &sta)
{
if (Graph[tmp.x+1][tmp.y]=='O')
{
Graph[tmp.x][tmp.y] = '#';
tmp.x = tmp.x + 1;
sta.push(tmp);
}
else if (Graph[tmp.x-1][tmp.y]=='O')
{
Graph[tmp.x][tmp.y] = '#';
tmp.x = tmp.x - 1;
sta.push(tmp);
}
else if (Graph[tmp.x][tmp.y+1]=='O')
{
Graph[tmp.x][tmp.y] = '#';
tmp.y = tmp.y + 1;
sta.push(tmp);
}
else if (Graph[tmp.x][tmp.y-1]=='O')
{
Graph[tmp.x][tmp.y] = '#';
tmp.y = tmp.y - 1;
sta.push(tmp);
}
else
{
tmp = sta.top();
Graph[tmp.x][tmp.y] = '#';
sta.pop();
}
}
int main()
{
int num, i, j;
while (cin>>num && num)
{
for (i=0; i<num; i++)
for (j=0; j<num; j++)
{
cin>>Graph[i][j];
if (Graph[i][j]=='s')
{ s.x = i, s.y = j;}
else if (Graph[i][j]=='t')
{t.x = i, t.y = j;}
}
stack<struct Node> sta;
sta.push(s);
while (!sta.empty())
{
tmp = sta.top();
if (Judge(sta))//下一步是否可达
break;
Advance(sta);//前进
}
if (sta.empty())
cout<<"找不到出口"<<endl;
else
{
j = i = sta.size();
while (!sta.empty())
{
order[i] = sta.top();
sta.pop();
i--;
}
for (i=1; i<=j; i++)
{
if (i==1)
cout<<'('<<order[i].x<<','<<order[i].y<<')';
else
cout<<"->("<<order[i].x<<','<<order[i].y<<')';
}
cout<<endl;
}

}
return 0;
}