希尔排序算法

#include <stdio.h>
 
void output_array(int data[], int n)
 {
     int i;
     for(i = 0; i < n; i++)
         printf("%d ", data[i]);
     printf("\n");
 }


 void swap(int *a, int *b)
 {
     int x;
     x = *a;
     *a = *b;
     *b = x;
 }


 void insertion_sort(int data[], int n, int increment)
 {
     int i, j;
     for(i = increment; i < n; i += increment)
         for(j = i; j >= increment && data[j] > data[j - increment]; j -= increment)
             swap(&data[j], &data[j - increment]);
 }


 void shellsort(int data[], int n)
 {
     int i, j;
     for(i = n / 2; i > 2; i /= 2)
         for(j = 0; j < i; j++)
             insertion_sort(data + j, n - j, i);
     insertion_sort(data, n, 1);
 }


 int main()
 {
     int data[] = {5, 3, 1, 665, 77, 66, 44, 11, 10, 9, 8, 6};
     output_array(data, 12);
     shellsort(data, 12);
     output_array(data, 12);
     return 0;
 }