使用栈解决迷宫问题

/******************************************************************************************
Copyright (c), Inc.(2016), All rights reserved.

Purpose: 使用栈解决迷宫问题

Author: 迷宫实现

Created Time: 2016_9
******************************************************************************************/
#pragma once
#include <stack>

struct Pos
{
int row; // 行
int col; // 列
};

int** CreateMaze(int n)
{
int** ppMaze = new int*
;
for (int i = 0; i < n; ++i)
{
ppMaze[i] = new int
;
memset(ppMaze[i], 0, sizeof(int)*n);
}

return ppMaze;
}

Pos InitMaze(int** ppMaze, int n)
{
Pos entry;
entry.row = 2;
entry.col = 0;

FILE* fOut = fopen("MazeMap.txt", "r");
for (int i = 0; i < n; ++i)
{
for (int j = 0; j < n;)
{
char ch = fgetc(fOut);
if (ch == '0' || ch == '1')
{
ppMaze[i][j++] = ch - '0';
}
else if (ch == EOF)
{
cout<<"Maze Map Error"<<endl;
}
}
}

fclose(fOut);

return entry;
}

void PrintMaze(int** ppMaze, int n)
{
for (int i = 0; i < n; ++i)
{
for (int j = 0; j < n; ++j)
{
cout<<ppMaze[i][j]<<" ";
}
cout<<endl;
}

cout<<endl;
}

bool CheckIsAccess(int** ppMaze, int n, Pos pos)
{
if (pos.col > 0 && pos.col < n
&& pos.row > 0 && pos.row < n
&& ppMaze[pos.row][pos.col] == 0)
{
return true;
}

return false;
}

bool Maze(int** ppMaze, int n, const Pos& entry, stack<Pos>& path)
{
assert(entry.col < n && entry.row < n);

Pos cur = entry;
ppMaze[cur.row][cur.col] = 2;
path.push(cur);

while (!path.empty())
{
Pos next = path.top();

//
// 出口在最后一行
//
if (next.row == n-1)
return true;

// 上
next.row -= 1;
if (CheckIsAccess(ppMaze, n, next))
{
ppMaze[next.row][next.col] = 2;
path.push(next);
continue;
}

// 右
next = path.top();
next.col += 1;
if (CheckIsAccess(ppMaze, n, next))
{
ppMaze[next.row][next.col] = 2;
path.push(next);
continue;
}

// 下
next = path.top();
next.row += 1;
if (CheckIsAccess(ppMaze, n, next))
{
ppMaze[next.row][next.col] = 2;
path.push(next);
continue;
}

// 左
next = path.top();
next.col -= 1;
if (CheckIsAccess(ppMaze, n, next))
{
ppMaze[next.row][next.col] = 2;
path.push(next);
continue;
}

Pos tmp = path.top();
ppMaze[tmp.row][tmp.col] = 3;
path.pop();
}

return false;
}

void TestMaze()
{
int n = 10;
int** ppMaze = CreateMaze(n);
Pos entry = InitMaze(ppMaze, n);
PrintMaze(ppMaze, n);

stack<Pos> path;
Maze(ppMaze, n, entry, path);
PrintMaze(ppMaze, n);

cout<<"Path:";
while (!path.empty())
{
const Pos& pos = path.top();
cout<<"("<<pos.row<<"，"<<pos.col<<")"<<"<-";
path.pop();
}

cout<<"Entry"<<endl;
}