各种排序算法的C++实现

#include <iostream>
#include <ctime>
#include <iterator>
#include <vector>
#include <algorithm>
#include <string>
using namespace std;
void bubble(vector<int> &a) //冒泡排序
{
    for(size_t i = 0; i < a.size() - 1; ++i)
    {
        for(size_t j = i + 1; j < a.size(); ++j)
        {
            if(a[j] < a[i])
            {
                swap(a[i], a[j]);
            }
        }
    }
}
void insert(vector<int> &a) //插入排序
{
    size_t j;
    for(size_t i = 1; i < a.size(); ++i)
    {
        int tmp = a[i];
        for(j = i; j > 0 && tmp < a[j - 1]; --j)
            a[j] = a[j - 1];
        a[j] = tmp;
    }
}
void shellsort(vector<int> &a)//希尔排序
{
    for(size_t gap = a.size() / 2; gap > 0; gap /= 2)
    for(size_t i = gap; i < a.size(); ++i)
    {
        int tmp = a[i];
        size_t j = i;
        for(; j >= gap && tmp < a[j - gap]; j-=gap)
            a[j] = a[j - gap];
        a[j] = tmp;
    }
}
int mypartition(vector<int> &a, int p, int r);
void quicksort(vector<int> &a, int i, int r)//算法导论的快速排序
{
    if(i < r)
    {
        int p = mypartition(a, i, r);
        quicksort(a, i, p - 1);
 quicksort(a, p + 1, r);
    }
}

int mypartition(vector<int> &a, int p, int r)
{
    int x = a[r];
    int i = p - 1;
    for(int j = p; j < r - 1; ++j)
    {
        if(a[j] <= x)
        {
            ++i;
            swap(a[j], a[i]);
        }
    }
    swap(a[i + 1], a[r]);
    return i + 1;
}
template<class T>
void percDown(vector<T> &a, int i, int n);
template<class T>
void headpsort(vector<T> &a)//堆排序
{
    for(int i = a.size() / 2; i >= 0; --i)
        percDown(a, i, a.size());
    for(int j = a.size() - 1; j > 0; --j)
    {
        swap(a[0], a[j]);
        percDown(a, 0, j);
    }
}
inline int leftChild(int i)
{
    return 2 * i + 1;
}
template<class T>
void percDown(vector<T> &a, int i, int n)
{
    int child;
    T tmp;
    for(tmp = a[i]; leftChild(i) < n; i = child)
    {
        child = leftChild(i);
        if(child != n - 1 && a[child] < a[child + 1])
            ++child;
        if(tmp < a[child])
           a[i] = a[child];
        else
            break;
    }
    a[i] = tmp;
}
template<class T>
void mergeSort(vector<T> &a, vector<T> &theArray, int left, int right);
template<class T>
void mergeSort(vector<T> &a)//归并排序
{
    vector<T> theArray(a.size());
    mergeSort(a, theArray, 0, a.size() - 1);
}
template<class T>
void mergeSort(vector<T> &a, vector<T> &theArray, int left, int right)
{
    if(left < right)
    {
        int center = (left + right) / 2;
        mergeSort(a, theArray, left, center);
        mergeSort(a, theArray, center + 1, right);
        mymerge(a, theArray, left, center + 1, right);
    }
}
template<class T>
void mymerge(vector<T> &a, vector<T> &theArray, int leftPos, int rightPos, int rightEnd)
{
    int leftEnd = rightPos - 1;
    int tmpPos = leftPos;
    int numElements = rightEnd - leftPos + 1;
    while(leftPos <= leftEnd && rightPos <= rightEnd)
    {
        if(a[leftPos] <= a[rightPos])
            theArray[tmpPos++] = a[leftPos++];
        else
            theArray[tmpPos++] = a[rightPos++];
    }
    while(leftPos <= leftEnd)
        theArray[tmpPos++] = a[leftPos++];
    while(rightPos <= rightEnd)
        theArray[tmpPos++] = a[rightPos++];
    for(int i = 0; i < numElements; ++i, --rightEnd)
        a[rightEnd] = theArray[rightEnd];
}
template<class T>
void insertionSort(vector<T> &a, int left, int right)//插入排序
{
    int j;
    for(int i = left; i <= right; ++i)
    {
        int tmp = a[i];
        for(j = i; j > 0 && tmp < a[j - 1]; --j)
  a[j] = a[j - 1];
        a[j] = tmp;
    }
}
template<class T>
void my_quicksort(vector<T> &a, int left, int right);//数据结构与算法分析的快速排序
template<class T>
void my_quicksort(vector<T> &a)
{
    my_quicksort(a, 0, a.size() - 1);
}
template<class T>
const T& median3(vector<T> &a, int left, int right)
{
    int center = (left + right) / 2;
    if(a[center] < a[left])
        swap(a[center], a[left]);
    if(a[right] < a[left])
        swap(a[right], a[left]);
    if(a[right] < a[center])
        swap(a[center], a[right]);
    swap(a[center], a[right - 1]);
    return a[right - 1];
}
template<class T>
void my_quicksort(vector<T> &a, int left, int right)
{
    if(left + 10 <= right)
    {
        T pivot = median3(a, left, right);
        int i = left, j = right - 1;
        for(;;)
        {
            while(++i,a[i] < pivot){}
            while(--j,pivot < a[j]){}
            if(i < j)
                swap(a[i], a[j]);
            else
                break;
        }
        swap(a[i], a[right - 1]);
        my_quicksort(a, left, i - 1);
        my_quicksort(a, i + 1, right);
    }
    else
    {
        insertionSort(a, left, right);

  }
}
template<class T>
class Pointer
{
public:
    Pointer(T *rhs = NULL) : pointee(rhs){}
    bool operator < (const Pointer& rhs) const
    {
        return *pointee < *rhs.pointee;
    }
    T* comp() const
    {
        return pointee;
    }
    T operator * () const
    {
        return *pointee;
    }
private:
    T *pointee;
};
template<class T>
bool operator != (const Pointer<T> &lhs, T* rhs)
{
    return lhs.comp() != rhs;
}
template<class T>
int operator - (const Pointer<T> &lhs,  T* rhs)
{
    return lhs.comp() - rhs;
}
template<class T>
void largeObjectSort(vector<T> &a)//通过指针排序
{
    vector<Pointer<T> > p(a.size());
    size_t i, j;
    int nextj;
    for(i = 0; i < a.size(); ++i)
    {
        p[i] = &a[i];
    }
    my_quicksort(a);
    for(i = 0; i < a.size(); ++i)
        if(p[i] != &a[i])
        {
            T tmp = a[i];
            for(j = i; p[j] != &a[i]; j = nextj)
            {
                nextj = p[j] - &a[0];
                a[i] = *p[j];
                p[j] = &a[j];
            }
            a[j] = tmp;
            p[j] = &a[j];
        }
}
int main()
{
    srand(time(NULL));
    vector<int> a(500000);
    for(size_t i = 0; i < a.size(); ++i)
        a[i] = rand() % 1000;
    //largeObjectSort(a);
   // copy(a.begin(), a.end(), ostream_iterator<int>(cout, " "));
    //cout << endl;
     //make_heap(a.begin(), a.end());
     //sort_heap(a.begin(), a.end());
     //sort(a.begin(), a.end());
     //sort(a.begin(), a.end(), less<int>());
     //stable_sort(a.begin(), a.end());
     //quicksort(a, 0 , a.size());
    //bubble(a);
    //insert(a);
    //shellsort(a);
    //headpsort(a);
     //mergeSort(a);
    //my_quicksort(a);
    //copy(a.begin(), a.end(), ostream_iterator<int>(cout, " "));
    return 0;
}

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