stooge sort

:Introduction to Algorithms P95

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

According to master method
T(n) = O(n^(log(2/3, 3) > O(n^2)

 

 

///////////////////Test Code/////////////////////////
#include "stdafx.h"
#include "stdlib.h"
#include <time.h>
#include "basic_algorithm.h"
#include <iostream>
using namespace std;


int _tmain(int argc, _TCHAR* argv[])
{
    
    srand((unsigned)time(NULL));
    int *arr = new int[20];
    for(int i = 0; i < 20; ++i)
    {
        arr[i] = rand() % 30;
    }
    enzo::stooge_sort(arr,20);
    for(int i = 0; i < 20; ++i)
    {
        cout << arr[i] << " ";
    }
    cout << endl;
    system("pause");
    return 0;
}

///////////////////Source Code///////////////////////
    template<typename _T>
    void stooge_sort(_T *arr, int n)
    {
        stooge_sort(arr, 0, n-1);
    }

    template<typename _T>
    void stooge_sort(_T *arr, int from, int to)
    {
        if(arr[to] < arr[from])
        {
            ez_swap(arr[to], arr[from]);
        }
        if(from + 1 < to)
        {
            int k = (to - from + 1) / 3;
            stooge_sort(arr, from, to - k);
            stooge_sort(arr, from + k, to);
            stooge_sort(arr, from, to - k);
        }
    }