每天一个小算法（Shell Sort2）

希尔排序：

伪代码：

input: an array a of length n with array elements numbered 0 to n − 1inc ← round(n/2)while inc > 0 do:        for i = inc .. n − 1 do:                temp ← a[i]                j ← i                while j ≥ inc and a[j − inc] > temp do:                        a[j] ← a[j − inc]                        j ← j − inc                a[j] ← temp        inc ← round(inc / 2)

C语言实现：

#include <stdio.h>#include <stdlib.h>#define LEN 10 int main(){     int i, j, temp;      int gap = 0;     int a[] = {10,9,8,7,6,5,4,3,2,1};      while (gap<=LEN)     {          gap = gap * 3 + 1;     }      while (gap > 0)      {         for ( i = gap; i < LEN; i++ )         {             j = i - gap;             temp = a[i];                          while (( j >= 0 ) && ( a[j] > temp ))             {                 a[j + gap] = a[j];                 j = j - gap;             }             a[j+gap] = temp;         }         gap = ( gap - 1 ) / 3;     }     for(i=0;i<LEN;i++) {  printf("%d\n",a[i]); } }