QuickSort

Program not like Math, has few but vast ways.
Program Pearls Series aims to find "the way".
算法珠玑系列，旨在写出SoTA的算法代码，这种实现，实现那唯一的实现

QuickSort

#include<iostream>
#include<vector>

using namespace std;

typedef int T;

void swap(vector<T>& v, int index1, int index2)
{
        T temp = v[index1];
        v[index1] = v[index2];
        v[index2] = temp;
}


int partition(vector<T>& v, int left, int right)
{
        int smaller = left;
        for (int i = left; i < right; ++i)
        {
                if (v[i] < v[right])
                {
                        swap(v, i, smaller);
                        ++smaller;
                }
        }
        // already find all smaller number
        swap(v, smaller, right);
        return smaller;
}

void quickSort(vector<T>& v, int left, int right)
{
        if(left < right)
        {
                int pi = partition(v, left, right);
                quickSort(v, left, pi-1);
                quickSort(v, pi+1, right);
        }
}

int main()
{
        vector<T> v = {1,2,3,5,0,34,1,39,13909, 888};
        quickSort(v, 0, v.size()-1);
        for (T e : v) std::cout << e << "\n";
}

以上即是快速排序。