TheAlgorithms-C/sorting/countingSort.c

#include <stdio.h>
#include<string.h>
/*
  > Counting sort is a sorting technique based on keys between a specific range.
  > integer sorting algorithm
  > Worst-case performance O(n+k)
  > Stabilized by prefix sum array
*/
int main()
{
   int i,n,l=0;
   scanf("%d",&n);
   int a[n];
   for(i=0;i<n;i++)
   {
  	  scanf("%d",&a[i]);
  	  if(a[i] > l)
  	   l = a[i];
   }
   int b[l+1];
   memset(b, 0, (l+1)*sizeof(b[0]));
   for(i=0;i<n;i++)
 	 b[a[i]]++; //hashing number to array index
    for(i=0;i<(l+1);i++) //unstable , stabilized by prefix sum array
 	{
 	  if(b[i]>0)
 	  {
 		 while(b[i]!=0) //for case when number exists more than once
 		 {
 		   printf("%d ",i); 
 		   b[i]--;
 		 }
       }
 	}
  return 0;
}