排序算法 beta

排序算法总结

参考
《数据结构与算法分析——C++描述（第三版）》

//Sort.h#ifndef SORT_H#define SORT_H#include <vector>#include <iostream>using namespace std;inline int leftChild (int i){    return 2*i+1;}template <typename T>class Sort{public:    explicit Sort(const vector<T>& k);//k的名称太难听了。。    void insertsort();    void mergesort();    void quicksort();    void shellsort();    void heapsort();    void print();    void restore();protected:    void quicksort(int left, int right);    void mergesort(vector<T>& tmpArray, int left, int right);    void merge(vector<T>& tmpArray, int leftPos, int rightPos, int rightEnd);    const T& median3(int left, int right);    void percDown(int i, int n);private:    vector<T> a;    vector<T> origin;};template <typename T>Sort<T>::Sort(const vector<T> &k){    a = k;    origin = k;};template <typename T>void Sort<T>::insertsort(){    int j;    for(int p = 1; p < a.size(); p++)    {        T tmp = a[p];        for(j = p; j > 0 && tmp < a[j-1]; j--)            a[j] = a[j-1];        a[j] = tmp;    }}template<typename T>void Sort<T>::quicksort(){    quicksort(0, a.size()-1);}template <typename T>void Sort<T>::quicksort(int left, int right){    if(left+2 <= right)    {        T pivot = median3(left, right);        int i = left, j = right-1;        for(; ;)        {            while(a[++i] < pivot) {}            while(pivot < a[--j]) {}            if(i < j)                swap(a[i], a[j]);            else                break;        }        swap(a[i], a[right-1]);        quicksort(left, i-1);        quicksort(i+1, right);    }}template <typename T>void Sort<T>::mergesort(){    vector<T> tmpArray(a.size());    mergesort(tmpArray, 0, a.size()-1);}template <typename T>void Sort<T>::mergesort(vector<T>& tmpArray, int left, int right){    if(left < right)    {        int center = (left+right)>>1;        mergesort(tmpArray, left, center);        mergesort(tmpArray, center+1, right);        merge(tmpArray, left, center+1, right);    }}template <typename T>void Sort<T>::shellsort(){    for(int gap = a.size()/2; gap > 0; gap /= 2)        for(int i = gap; i < a.size(); i++)        {            T tmp = a[i];            int j = i;            for(; j >= gap && tmp < a[j-gap]; j -= gap)                a[j]= a[j-gap];            a[j] = tmp;        }}template <typename T>void Sort<T>::heapsort(){    //建堆    for(int i = a.size()/2; i >= 0; i--)        percDown(i, a.size());    for(int j = a.size()-1; j > 0; j--)    {        swap(a[0], a[j]);        percDown(0, j);    }}template <typename T>void Sort<T>::percDown(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 <typename T>void Sort<T>::merge(vector<T> &tmpArray, int leftPos, int rightPos, int rightEnd){    int leftEnd = rightPos-1;    int tmpPos = leftPos;    int numElement = rightEnd-leftPos+1;    while(leftPos <= leftEnd && rightPos <= rightEnd)        if(a[leftPos] <= a[rightPos])            tmpArray[tmpPos++] = a[leftPos++];        else            tmpArray[tmpPos++] = a[rightPos++];    //copy rest of first half    while(leftPos <= leftEnd)        tmpArray[tmpPos++] = a[leftPos++];    while(rightPos <= rightEnd)        tmpArray[tmpPos++] = a[rightPos++];    //copy to    for(int i = 0; i < numElement; i++, rightEnd--)        a[rightEnd] = tmpArray[rightEnd];}template <typename T>const T & Sort<T>::median3(int left, int right){    int center = (left+right)>>1;    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[right], a[center]);    //将 pivot 放在 right-1位置    swap(a[center], a[right-1]);    return a[right-1];}template <typename T>void Sort<T>::print(){    for(size_t i = 0; i < a.size(); i++)        cout<<a[i]<<",";    cout<<endl;}template <typename T>void Sort<T>::restore(){    a = origin;}#endif // SORT_H

//main.cpp for testing#include "Sort.h"int main(){    int tmp[] = {4, 6, 2, 1, 0, 7, 22, 12, 5,3 };    size_t size = sizeof(tmp)/sizeof(int);    cout<<size<<endl;    vector<int> a;    for(size_t i = 0; i < size; i++)        a.push_back(tmp[i]);    Sort<int> test(a);    cout<<"==test sorting arigthms:=="<<endl;        cout<<"test insert sort"<<endl;    cout<<"origin array"<<endl;    test.restore();    test.print();    cout<<"sorted array"<<endl;    test.insertsort();    test.print();    cout<<"test shell sort"<<endl;    cout<<"origin array"<<endl;    test.restore();    test.print();    cout<<"sorted array"<<endl;    test.shellsort();    test.print();    cout<<"test merge sort"<<endl;    cout<<"origin array"<<endl;    test.restore();    test.print();    cout<<"sorted array"<<endl;    test.mergesort();    test.print();        cout<<"test quick sort"<<endl;    cout<<"origin array"<<endl;    test.restore();    test.print();    cout<<"sorted array"<<endl;    test.quicksort();    test.print();    return 0;}