Stooge Sort

注：本博文来自Yang Enzo博客园，感谢作者整理。

 

:Introduction to Algorithms P95

T(n) = 3 * T(2*n/3) + O(1)

According to master method,this situation suits the first case.

 1 ///////////////////Test Code/////////////////////////

 2 #include "stdafx.h"

 3 #include "stdlib.h"

 4 #include <time.h>

 5 #include "basic_algorithm.h"

 6 #include <iostream>

 7 using namespace std;

 8 

 9 

10 int _tmain(int argc, _TCHAR* argv[])

11 {

12     

13     srand((unsigned)time(NULL));

14     int *arr = new int[20];

15     for(int i = 0; i < 20; ++i)

16     {

17         arr[i] = rand() % 30;

18     }

19     enzo::stooge_sort(arr,20);

20     for(int i = 0; i < 20; ++i)

21     {

22         cout << arr[i] << " ";

23     }

24     cout << endl;

25     system("pause");

26     return 0;

27 }

28 

29 ///////////////////Source Code///////////////////////

30     template<typename _T>

31     void stooge_sort(_T *arr, int n)

32     {

33         stooge_sort(arr, 0, n-1);

34     }

35 

36     template<typename _T>

37     void stooge_sort(_T *arr, int from, int to)

38     {

39         if(arr[to] < arr[from])

40         {

41             ez_swap(arr[to], arr[from]);

42         }

43         if(from + 1 < to)

44         {

45             int k = (to - from + 1) / 3;

46             stooge_sort(arr, from, to - k);

47             stooge_sort(arr, from + k, to);

48             stooge_sort(arr, from, to - k);

49         }

50     }

 

T(n) = O(n^(log(2/3, 3) > O(n^2)