Thread: Segmentation fault in beginning or program

I have got the program running but when I enter the filename of the txt file it gives me a segmentation fault and ends.. Could someone please help me out..

Code:

#include <stdio.h>
#include <stdlib.h>

#define NUMROWS 20
#define NUMCOLS 20
#define INFINITY 999999

int read_maze(char [][], int *, int *);
void display_maze(char [][]);
void copy_maze(char [][], char[][]);
void solve_maze(char [][], int, int, int);

char mazeBest[NUMROWS][NUMCOLS]; /* Stores best maze found so far. */
int lengthBest = INFINITY; /* Stores length of best maze found so far. */

int main(int argc, char **argv){
    FILE *outFile = fopen("pathfile.txt", "w");

  char maze[NUMROWS][NUMCOLS]; /* Stores maze read from input file. */
  int startRow, startCol; /* Starting point in maze. */
  if (read_maze(maze, &startRow, &startCol) == 0)
    {
      printf("Error reading maze from file robotfile.txt!\n");
      return;
    }

  printf("Starting maze:\n");
  display_maze(maze);
  solve_maze(maze, startRow, startCol, 0);
  if (lengthBest == INFINITY)
    {
      printf("\nNo path to goal was found in maze!\n");
      return;
    }
  else
    {
      printf("\nBest solution found:\n");
      display_maze(mazeBest);
   }

  return;
}

/*
 * Read maze from "robotfile.txt".
 * Fill in *sRow and *sCol with position of 'O'.
 * If error, return 0, else return 1.
 */
int read_maze(char maze[NUMROWS][NUMCOLS], int *sRow, int *sCol)
{
      char filename;
      printf("Enter the name of the maze file. \n");
      scanf("%s", filename);
      FILE *inFile = fopen("filename", "r");
      int row, col;

  /* Open maze text file, make sure it opens OK. */
  if ((inFile = fopen("robotfile.txt", "r")) == NULL)
{
      char filename;
      printf("Enter the name of the maze file. \n");
      scanf("%s", filename);
      FILE *inFile = fopen("filename", "r");
      int row, col;

  /* Open maze text file, make sure it opens OK. */
  if ((inFile = fopen("robotfile.txt", "r")) == NULL)
    return 0;

  /* Loop through the rows. */
  for (row = 0; row < NUMROWS; row++)
    {
      /* Loop through the column in current row. */
      for (col = 0; col < NUMROWS; col++)
        {
          maze[row][col] = getc(inFile);
          /* Check if this is the starting position. */
  if (maze[row][col] == 'O')
            {
              *sRow = row;
              *sCol = col;
            }
        }
      /* Ignore newline at end of each row. */
      getc(inFile);
    }
         fclose(inFile);

  return 1;
}

/* Display the maze passed as a parameter to standard output. */
void display_maze(char maze[NUMROWS][NUMCOLS])
{
  int row, col;
  for (row = 0; row < NUMROWS; row++)
    {
      for (col = 0; col < NUMCOLS; col++)
        {
          putchar(maze[row][col]);
        }
      putchar('\n');
    }

  return;
}

/* Copy the maze in mazeSrc to mazeDest. */
void copy_maze(char mazeSrc[NUMROWS][NUMCOLS],
               char mazeDest[NUMROWS][NUMCOLS])
{
  int row, col;

  for (row = 0; row < NUMROWS; row++)
    {
 for (col = 0; col < NUMCOLS; col++)
        {
          mazeDest[row][col] = mazeSrc[row][col];
        }
    }

  return;
}

/*
 * Given:
 *    (1) maze with path so far
 *    (2) current row
 *    (3) current column
 *    (4) length of path so far
 * The function solve_maze recursively tries to solve the maze.
 *
 * When a solution is found, compare it to previous best found solution,
 * and update appropriate globals if necessary.
 */
void solve_maze(char mazeCur[NUMROWS][NUMCOLS], int curRow, int curCol,
int length)
{
  /* If already as long as best solution, no need to look further. */
  if (length >= lengthBest)
    return;

  /* Check if solution found. */
  if ((mazeCur[curRow-1][curCol] == 'X') ||
      (mazeCur[curRow+1][curCol] == 'X') ||
     (mazeCur[curRow][curCol+1] == 'X') ||
      (mazeCur[curRow][curCol-1] == 'X'))
    {
      /* Found solution, better then previous best, update globals. */
      lengthBest = length;
      copy_maze(mazeCur, mazeBest);
      return;
    }

  /* Recurse in each possible direction that is empty. */
  if (mazeCur[curRow-1][curCol] == ' ')
    {
      mazeCur[curRow-1][curCol] = 'O';
      solve_maze(mazeCur, curRow-1, curCol, length+1);
      mazeCur[curRow-1][curCol] = ' ';
    }
  if (mazeCur[curRow+1][curCol] == ' ')
    {
      mazeCur[curRow+1][curCol] = 'O';
      solve_maze(mazeCur, curRow+1, curCol, length+1);
     mazeCur[curRow+1][curCol] = ' ';
    }
  if (mazeCur[curRow][curCol-1] == ' ')
    {
      mazeCur[curRow][curCol-1] = 'O';
      solve_maze(mazeCur, curRow, curCol-1, length+1);
      mazeCur[curRow][curCol-1] = ' ';
    }
  if (mazeCur[curRow][curCol+1] == ' ')
    {
     mazeCur[curRow][curCol+1] = 'O';
      solve_maze(mazeCur, curRow, curCol+1, length+1);
      mazeCur[curRow][curCol+1] = ' ';
    }

  return;
}