For the maze program, with '*' indicating a wall, ' ' indicating a corridor, and '#' indicating a solution path, where I have to use a recursive backtracking algorithm, I am still having trouble print the maze solution. Here is the unsolved maze:

8 12
 **********
 * * *
 * ****** *
 ***** *
 * ******
 *** *** *
 * ** *
 ********** 

Here is the solved maze:

##**********
 *#*########*
 *###******#*
 *****######*
 * ###******
 ***#***####*
 * #####**#*
 **********##

Here is my updated solution:

#include<iostream>
#include<fstream>
using namespace std;

#define MAXROW 24 // Maximum number of rows
#define MAXCOL 81 // Maximum number of columns

// Read a maze from a file.
void readMaze(ifstream &in, int &rows, int &columns, char a[MAXROW][MAXCOL])
{    
    in >> rows >> columns;
    cout << rows << " " << columns << endl;
    in.getline(a[0],sizeof a[0]);
    for(int i = 0; i < rows; i++)
    {
        in.getline(a[i], sizeof a[i]);
    }
}

// Print the maze.
void printMaze(int &rows, int &columns, char a[MAXCOL][MAXCOL])
{   
    for(int i = 0; i < rows; i++)
    {
        for(int j = 0; j < columns; j++)
        {
            cout << a[i][j];
        }
        cout << endl;
    }
}

// Solve the maze using recursion.
bool solveMaze(int rows, int columns, char a[MAXROW][MAXCOL])
{
    // If outside the maze, return false.
    if(rows < 0 || rows > MAXCOL-1 || columns < 0 || columns > MAXROW-1)
    {
        return false;
    }
    // If there is a wall, return false.
    if(a[columns][rows] == '*')
    {
        return false;
    }
    // Mark solution path.
    a[columns][rows] = '#';
    // If able to move up, return true.
    if(solveMaze(rows,columns-1,a))
    {
        return true;
    }
    // If able to move right, return true.
    if(solveMaze(rows+1,columns,a))
    {
        return true;
    }
    // If able to move down, return true.
    if(solveMaze(rows,columns+1,a))
    {
        return true;
    }
    // If able to move left, return true.
    if(solveMaze(rows-1,columns,a))
    {
        return true;
    }
    // Mark repeated paths.
    a[columns][rows] = 'x';
    return false;
}

int main()
{
    char inFile[20];
    char a[MAXROW][MAXCOL];
    ifstream in;
    int rows, columns;

    // Prompt user for file name.
    cout << "Enter file name: ";
    cin >> inFile;

    // Check for file open errors.
    if(!inFile)
    {
        cout << "Error" << endl;
        return -1;
    }

    // Open the file.
    in.open(inFile);

    cout << "Maze before solution: " << endl;
    readMaze(in,rows,columns,a);
    printMaze(rows,columns,a);
    cout << "Maze after solution: " << endl;
    solveMaze(rows,columns,a);
    printMaze(rows,columns,a);

    // Close the file.
    in.close();
    return 0;
}

I made a few changes to my code and I still cannot get the solved maze output. Is there anything else I need to change/fix?

Here is the output I am getting:

Enter file name: maze.txt
Maze before solution:
8 12
  **********
* *        *
*   ****** *
*****      *
*     ******
*** ***    *
*       ** *
**********
Maze after solution:

Here is the expected output:

Enter file name: maze.txt
Maze before solution:
8 12
  **********
* *        *
*   ****** *
*****      *
*     ******
*** ***    *
*       ** *
**********
Maze after solution:
##**********
*#*########*
*###******#*
*****######*
*  ###******
***#***####*
*  #####**#*
**********##

Edited 3 Years Ago by andrew mendonca

The solution is not printed because you have not used PrintMaze function in your SolveMaze function.

Write printMaze(rows, columns, a[MAXCOL][MAXCOL]) at line 68.

Edited 3 Years Ago by kal_crazy: wrong lines

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