Program which displays the all signed short numbers

Question

*EDIT: I Deleted by mistake the remarks I wrote on that using short & char is kind of obsolete / not efficient in modern programming. this one is just for practice basic stuff.**

This program creates and prints the series of signed short values starting from their equivalent in the unsigned short "space/world" starting at value 0 .

**example : on a machine where short is 16 bit :
unsigned short : 0 1 2 .... 65535
=> signed short : 0 1 2 ... 32766 -32767 -32766 -32765 ... -2 -1

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

//Initialize memory pointed by p with values 0 1 ... n
//Assumption : the value of n can be converted to 
//             short int (without over/under-flow)
unsigned int initArr (short int *p, unsigned int n);

int main (void)
{
  const unsigned int lastNumInSeq = USHRT_MAX;
  short *p_arr = (short *) malloc ( (lastNumInSeq + 1) * sizeof (short));
  short int lastValSet = initArr (p_arr, lastNumInSeq); //returns the "max" val written

//  for (unsigned i = 0; i < numOfElem; i++)
//      printf ("[%d]=%d \n", i, (*(p_arr + i)));

  printf ("lastValSet = %d *(p_arr + lastNumInSeq) = %d  ",
           lastValSet,*(p_arr + lastNumInSeq ));

  return 0;
}

unsigned int initArr (short *p, unsigned int n)
{
  unsigned int offset,index = 0;

  while (index <= n){
      offset = index;
      *(p + offset) = ++index -1 ;
  }

  return offset;

Answer 1

There are some other cleanups needed.

The function signature should change from

    short initArr (short *p, unsigned int n);

to

    unsigned int initArr (short *p, unsigned int n);

The variable 'lastValSet' should change its type to unsigned int.

This comment is also confusing:

    //Assumption : the value of n can be converted to 
    //             short int (without over/under-flow)

It should be something like:

    //Assumption : the value of n which is of type int can be converted to 
    //             short int (without over/under-flow) up to 32767 which is the 
    //             max value for a variable of short type.