Segmantation fault with pointers

[MisterWhite]

I tried to make a maze solving function as part of the labyrinth game. I get segmentation fault on if(checkBoundries()) (code is below). is the mistake in the function call or there's some logic issue?

Spoiler

int checkBoundries(int currX,int currY,int rows,int columns, char **map)
{
    if( (currX>=0 && currX<=rows-1) && (currY>=0 && currY<=columns-1) )
    {

        if(map[currX][currY]!='#')
            return 1;
    }
    return 0;
}

int solveMaze(int rows, int columns,int currX, int currY, char ***map)// need fixing
{
    if(checkBoundries(currX,currY,rows,columns,*map))
    {
        if( (*map)[currX][currY]=='$')// base case
        {
            (*map)[currX][currY]='@';
            return 1;
        }
        (*map)[currX][currY]='.';

        //going right
        if(solveMaze(rows,columns,currX,currY+1,map)==1 )
            return 1;
        //left
        if(solveMaze(rows,columns,currX,currY-1,map)==1)
            return 1;
        //down
        if(solveMaze(rows,columns,currX+1,currY,map)==1)
            return 1;
        //up
        if(solveMaze(rows,columns,currX-1,currY,map)==1)
            return 1;

        //if there is no solution - undo
        (*map)[currX][currY]=' ';
        return 0;
    }
    return 0;
}

 

this is how i call solveMaze():

solveMaze(rows,columns,move.x,move.y,&map);// char **map; move.x/y current possition, rows/columns dimensions of maze

 

'.' - solution path marking

' ' - possible way

'@' - current possition

'#' - wall

'$'  - finish line.

[yavuz650]

you should try your luck at stackoverflow.

[mathijs727]

Use a debugger like the ones included in Visual Studio or Xcode, GDB (if you compile with GCC), LLDB (if you compile with LLVM/Clang), Valgrind, etc.

Writing a C++ program without a debugger is almost impossible.

[MisterWhite]

Just now, mathijs727 said:

Use a debugger like the ones included in Visual Studio or Xcode, GDB (if you compile with GCC), LLDB (if you compile with LLVM/Clang), Valgrind, etc.

Writing a C++ program without a debugger is almost impossible.

i used it.

first error is in

if(checkBoundries(currX,currY,rows,columns,*map))

second and third repeat like 5 times with the same values here

 if(solveMaze(rows,columns,currX,currY+1,map)==1 )
            return 1;
        //left
        if(solveMaze(rows,columns,currX,currY-1,map)==1)
            return 1;

 

[MisterWhite]

Spoiler

int getMapFromFile(char ***map)
{
  FILE *load=fopen("map.txt","r");
  *map=malloc(sizeof(char*)*20);//max 20 rows
  int rows=0;
 while(!foef(load))
 {
   (*map)[rows]=malloc(sizeof(char)*30);// max 30 columns
   fgets((*map)[rows],30,laod);
   rows++;
 }
  return rows;
}

int main()
{
	char **map;
  	int rows;
  
  rows=getMapFromFile(&map);
}

 

I really don't think that how i allocated memory for map is the issue because it works fine in other functions that are in the program.

Though is this function call correct

checkBoundries(currX,currY,rows,columns,*map)

?

[fizzlesticks]

if( (currX>=0 && currX<=rows-1) && (currY>=0 && currY<=columns-1) )

You have the X position checking against rows and Y checking columns, is that intentional? Most people would do it the other way.

 

edit: nvm looks like you have it the same everywhere.

[Unimportant]

int getMapFromFile(char ***map)

Being a 3 star programmer is not a compliment. You're doing something very wrong if you have to resort to this imho. It's a telltale sign your code needs to be simplified, which will probably solve the bug in the process.

 

I'd flatten the whole thing out into a normal 1D array and simply use index arithmetic to access rows/columns. It'll be less of a memory management hassle and passing the array along to functions will be much cleaner. The index arithmetic can be neatly wrapped in some accessor functions.

[Nineshadow]

What happens if you parse the map by reference and not by its pointer?

[MisterWhite]

1 hour ago, Nineshadow said:

What happens if you parse the map by reference and not by its pointer?

in which part? when getting the map from file?

sorry i'm a bit confused.

[MisterWhite]

Asked my professor today about this. It appears that here is an infinite recursion because I don't check if the we were here already. e.g. the cursor is in the right most position (next block is a wall) the recursive call goes back one step and the right again and so on.