Sortiranje dinamickog niza rastuci poredak insertion sort

#include <stdio.h>
#include <stdlib.h>
#define N 100

/* run this program using the console pauser or add your own getch, system("pause") or input loop */

void main()
{
    while(1)
        {
            int i;

            printf("Unesite duzinu niza n: "); int n; scanf("%d",&n);
            if (n<=0 || n>N) break;

            int *a = malloc(n*sizeof(int));
            printf("\nPocetni niz izgleda ovako: \n\n");
            for (i=0; i<n;i++)
            {
                printf("%d ",a[i] = rand()/(RAND_MAX + 1.)*10);
                if (i%30==29 || i==n-1) printf("\n");
            }

            for (i=1; i<n; i++)
            {
                int b=a[i], j=i-1;
                while(j>=0 && a[j]>b) { a[j+1] = a[j]; j--; }
                a[j+1]=b;
            }

            printf("\nUredjenji niz izgleda ovako:\n\n");
            for(i=0;i<n;i++)
            {
                printf("%d ",a[i]);
                if (i%30==29 || i==n-1) printf("\n");
            }
            printf("\n");
            free(a);

        }
}