C++ 算法之希尔排序详解及实例

#include <iostream> 
#include <Windows.h> 
#include <assert.h> 
 
using namespace std; 
 
//希尔排序,从小到大排 
void ShellSort(int* arr, int len)  
{ 
  assert(arr); 
  int gap = 3;   //先给一个初始组间距，gap为1时即为直接插入排序 
  for (gap = 3; gap > 0; --gap)  //不断缩小组间距，直到gap=1 
  { 
    for (int i = 0; i < len; ++i)    
    { 
      for (int j = i + gap; j < len; j = j + gap) 
      { 
        if (arr[j-gap] > arr[j]) 
        { 
          int temp = arr[j];  //将arr[j]处的值先保存起来 
          arr[j] = arr[j-gap]; 
          arr[j-gap] = temp; 
        } 
      } 
    } 
  } 
} 

#include "ShellSort.h" 
 
void TestShellSort() 
{ 
  int arr[] = { 100, 2,888, 6, 10, 5, 3, 666, 78, 9, 10000, 45, 67, 33 }; 
  int len = sizeof(arr) / sizeof(arr[0]); 
  cout << "未排序序列：" << ""; 
  for (int i = 0; i < len; ++i) 
  { 
    cout << arr[i] << "->"; 
  } 
  cout << endl; 
  ShellSort(arr, len); 
  cout << "已排序序列：" << ""; 
  for (int j = 0; j < len; ++j) 
  { 
    cout << arr[j] << "->"; 
  } 
  cout << endl; 
} 
 
int main() 
{ 
  TestShellSort(); 
  system("pause"); 
  return 0; 
}