Quicksort

I need to write a program that will be printed to the screen and to a text file. I need to test the function in a radom array of positive integers less than 100 of dimenstion 50.

#include <stdio.h> #define MAXNUMS 2000 void quicksort (int *a, int lft_bnd, int rt_bnd); void swap (int a[], int i, int j); void print_arr (int a[], int nums); main (int argc, char * argv[]) { char filenm[20]; int dataarray [MAXNUMS]; int num_nums=0, i, eof; FILE *fopen(), *flpt; void print_arr (int dataarray[], int num_nums); if (argc !=2) { printf ("proper invocation: pgm datafile\n"); exit(0); //call to undefined function 'exit' in function main[int, char **] } flpt = fopen(argv[1],"r"); //extra parameter in call to fopen() in function main[int, char **] if (flpt == NULL) { printf ("Open failed, check data filename\n"); exit(1); } eof = fscanf(flpt, "%d", &dataarray[num_nums]); num_nums=num_nums+1; while (eof >0) { eof = fscanf(flpt, "%d", &dataarray [num_nums]); num_nums=num_nums+1; if (num_nums>2000) { printf ("too many numbers, increase array size and recompile\n"); exit (2); } } num_nums=num_nums-1; printf ("sorting %d numbers \n", num_nums); printf ("the unsorted numbers are:"); print_arr (dataarray, num_nums); quicksort (dataarray, 0, num_nums-1); printf ("the sorted numbers are: "); print_arr (dataarray, num_nums); } void quicksort (int*a, int lft_bnd, int rt_bnd) { int i, lft_ptr, x, rt_ptr, pivot; void swap (int a[], int i, int j); if (lft_bnd >= rt_bnd) return; pivot = lft_bnd; lft_ptr= lft_bnd; rt_ptr=rt_bnd; x=a[pivot]; while (lft_ptr < rt_ptr) { while ((a[lft_ptr] <= x) && (lft_ptr < rt_ptr)) lft_ptr = lft_ptr +1; while (a[rt_ptr] >x) rt_ptr = rt_ptr -1; if (lft_ptr < rt_ptr) swap(a, lft_ptr, rt_ptr); } a[lft_bnd]=a[rt_ptr]; a[rt_ptr]=x; quicksort(a, lft_bnd, rt_ptr-1); quicksort(a, rt_ptr+1, rt_bnd); } void swap (int a[], int i, int j) { int temp; temp = a[i]; a[i] = a[j]; a[j] = temp; } void print_arr (int a[], int nums) { int i; for (i=0; i<nums; i=i+1) { if (i%10==0) printf("\n"); printf("%3d ",a[i]); } printf ("\n"); }