点击这里

Shell排序是一种高效的排序算法，基于插入排序算法。 该算法避免了大的移位，如插入排序的情况，如果较小的值是最右边的并且必须移动到最左边。

用C实现 (Implementation in C)

#include <stdio.h>
#include <stdbool.h>
#define MAX 7
int intArray[MAX] = {4,6,3,2,1,9,7};
void printline(int count) {
   int i;
   for(i = 0;i < count-1;i++) {
      printf("=");
   }
   printf("=\n");
}
void display() {
   int i;
   printf("[");
   // navigate through all items 
   for(i = 0;i < MAX;i++) {
      printf("%d ",intArray[i]);
   }
   printf("]\n");
}
void shellSort() {
   int inner, outer;
   int valueToInsert;
   int interval = 1;   
   int elements = MAX;
   int i = 0;
   while(interval <= elements/3) {
      interval = interval*3 +1;
   }
   while(interval > 0) {
      printf("iteration %d#:",i); 
      display();
      for(outer = interval; outer < elements; outer++) {
         valueToInsert = intArray[outer];
         inner = outer;
         while(inner > interval -1 && intArray[inner - interval] 
            >= valueToInsert) {
            intArray[inner] = intArray[inner - interval];
            inner -=interval;
            printf(" item moved :%d\n",intArray[inner]);
         }
         intArray[inner] = valueToInsert;
         printf(" item inserted :%d, at position :%d\n",valueToInsert,inner);
      }
      interval = (interval -1) /3;
      i++;
   }          
}
int main() {
   printf("Input Array: ");
   display();
   printline(50);
   shellSort();
   printf("Output Array: ");
   display();
   printline(50);
   return 1;
}

如果我们编译并运行上面的程序，它将产生以下结果 -

输出 (Output)

Input Array: [4 6 3 2 1 9 7 ]
==================================================
iteration 0#:[4 6 3 2 1 9 7 ]
 item moved :4
 item inserted :1, at position :0
 item inserted :9, at position :5
 item inserted :7, at position :6
iteration 1#:[1 6 3 2 4 9 7 ]
 item inserted :6, at position :1
 item moved :6
 item inserted :3, at position :1
 item moved :6
 item moved :3
 item inserted :2, at position :1
 item moved :6
 item inserted :4, at position :3
 item inserted :9, at position :5
 item moved :9
 item inserted :7, at position :5
Output Array: [1 2 3 4 6 7 9 ]
==================================================