C Shell Sort

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
// ww  w.  j  a  v  a 2s  .c o m
void shell(char *items, int count)
{
  int i, j, gap, k;
  char x, a[5];

  a[0]=8; a[1]=5; a[2]=3; a[3]=2; a[4]=1;

  for(k=0; k < 5; k++) {
    gap = a[k];
    for(i=gap; i < count; ++i) {
      x = items[i];
      for(j=i-gap; (x < items[j]) && (j >= 0); j=j-gap){
        items[j+gap] = items[j];
      }
      items[j+gap] = x;
    }
  }
}

int main(void)
{
  char s[255]="asdfasdfasdfasdfasdf";

  shell(s, strlen(s));
  printf("The sorted string is: %s.\n", s);

  return 0;
}