Thread: Segmentation fault

I am pretty new to programming and I am getting a segmentation fault and I have no idea where this is happening.

Code:

#include <stdio.h>
#include <stdlib.h>
#define FIELDWIDTH 3 //The width of the hopscotch field.


FILE *in;   //Pointer to files
FILE *out;


int max_score(int *tally_row, int middle_index);
int** alloc_no_of_marbles(int field_length, int fieldWidth);
int** alloc_score_of_each_square(int field_length, int fieldWidth);


int main(void)
{
    char inFileName[] = "hopscotch.dat";   //Open files for reading
    char outFileName[] = "hopscotch.out";


    int field_length, i, j;


    fscanf(in, "%d", &field_length);


    int **no_of_marbles = alloc_no_of_marbles(field_length, FIELDWIDTH);
    int **score_of_each_square = alloc_score_of_each_square(field_length, FIELDWIDTH);


    for(i=0; i<field_length; i++)
    {
        for(j=0; j<FIELDWIDTH; j++)
        {
            fscanf(in, "%d", &no_of_marbles[i][j]);
        }
    }


    for(i=0; i<field_length; i++)
    {
        for(j=0; j<FIELDWIDTH; j++)
        {
            score_of_each_square[i][j] =
            ( ((i-1) < 0) ? 0 : score_of_each_square[i-1][max_score(score_of_each_square[i-1],j)] )
            + no_of_marbles[i][j];
        }
    }


    int path_score = score_of_each_square[field_length-1][max_score(score_of_each_square[field_length-1],1)];
    char hop_path[field_length+1];
    int current_row = field_length, current_pos = 1, previous_pos;


    for(i=current_row; i>=0; i--)
    {
        if(i==0) previous_pos = 1;
        else previous_pos = max_score(score_of_each_square[i-1], current_pos);
        switch(current_pos - previous_pos){
            case -1: hop_path[i] = 'L';
            break;
            case 0: hop_path[i] = 'D';
            break;
            case 1: hop_path[i] = 'R';
            break;
        }
    current_pos = previous_pos;
    }


    fprintf(out, "Maximum possible score: %d\n", path_score);
    fprintf(out, "A path that achieves this score: ");
    for(i=0; i<=field_length; i++)
    fprintf(out, "%c", hop_path[i]);
    fprintf(out, "\n");
    return 0;
}


int max_score(int* tally_row, int middle_index){ 
    int k, value = 0, max_value_index = -1;
    for(k=middle_index-1; k<=middle_index+1; k++)
    {
        if(k >= 0 && k < FIELDWIDTH)
            if(tally_row[k] > value)
            {
                value = tally_row[k];
                max_value_index = k;
            }
    }
    return max_value_index;
} 


int **alloc_no_of_marbles(int field_length, int fieldWidth)
{
    int **hopArr;
    int *aux1;
    int i, j;
    aux1 = (int *) malloc(field_length*fieldWidth*sizeof(int));
    if (aux1 == NULL) exit(1);
    hopArr = (int **) malloc(field_length*sizeof(int *));
    if(hopArr == NULL) exit(1);
    for(i=j=0; i<field_length; i++, j+=fieldWidth)
    hopArr[i] = &aux1[j];
    return hopArr;
} 


int **alloc_score_of_each_square(int field_length, int fieldWidth)
{
    int **talArr;
    int *aux2;
    int i, j;
    aux2 = (int *) malloc(field_length*fieldWidth*sizeof(int));
    if (aux2 == NULL) exit(1);
    talArr = (int **) malloc(field_length*sizeof(int *));
    if(talArr == NULL) exit(1);
    for(i=j=0; i<field_length; i++, j+=fieldWidth)
    talArr[i] = &aux2[j];
    return talArr;
}