快速排序（基于顺序容器vector；基于数组array）

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代码1：基于顺序容器vector

  1 /*  2  * FILE: quick_sort_vector.cpp  3  * ---------------------------  4  * DATE: 20170818  5  * 快速排序，基于顺序容器vector  6  */  7   8 #include <iostream>  9 #include <vector> 10  11 /* 12  * Implementation notes: partition 13  * ------------------------------- 14  * This function rearrange the elements of the vector  15  */ 16  17 int partition(std::vector<int> &v, int begin, int end) 18 { 19         int pivot = v[begin]; 20         int left = begin + 1; 21         int right = end; 22         while(true) 23         { 24                 while(left < right && v[right] >= pivot) 25                         right--; 26                 while(left < right && v[left] < pivot) 27                         left++; 28                 if(left == right) 29                         break; 30                 std::swap(v[left], v[right]); 31         } 32         if(v[left] >= pivot) 33                 return begin; 34         v[begin] = v[left]; 35         v[left] = pivot; 36         return left; 37 } 38  39 /* 40  * Implementation notes: quickSort 41  * ------------------------------- 42  * This function sorts the elements in the vector between  43  * index position begin and end, inclusive 44  */ 45 void quickSort(std::vector<int> &v, int begin, int end) 46 { 47         if(begin >= end) 48                 return; 49         int boundary = partition(v, begin, end); 50         quickSort(v, begin, boundary - 1); 51         quickSort(v, boundary + 1, end); 52 } 53  54 /* 55  * Implemention notes: sort 56  * ------------------------ 57  * This function sorts the elements of the vector into  58  * increasing numerical order using the QuickSort algorithm 59  */ 60 void sort(std::vector<int> &v) 61 { 62         quickSort(v, 0, v.size() - 1); 63 } 64  65 void display(std::vector<int> &v) 66 { 67         for(std::vector<int>::iterator iter= v.begin(); iter != v.end(); iter++ ) 68                 std::cout<< *iter << "  "; 69         std::cout<< std::endl; 70 } 71  72 int main(int argc, char *argv[]) 73 { 74         int a[] ={3,4,2,1,7,5,8,9,0,6}; 75         std::vector<int> vec(a, a+10); 76         sort(vec); 77         display(vec); 78         return 0; 79 }

代码2：基于数组array

  1 /*  2  * FILE: quick_sort.cpp  3  * --------------------  4  * DATE: 20170818  5  *  6  *  7  */  8   9 #include <iostream> 10  11 void quickSort(int a[], int begin, int end); 12  13 int main(int argc, char *argv[]) 14 { 15         int a[] = {3,4,2,1,7,5,8,9,0,6}; 16         int length = sizeof(a) / sizeof(int); 17  18         quickSort(a, 0, length-1);      // 快速排序 19  20         for(int i = 0; i < length; i++) 21                 std::cout<< a[i] << "  "; 22         std::cout<< std::endl; 23         return 0; 24 } 25  26 /* 快速排序 */ 27 void quickSort(int a[], int begin, int end) 28 { 29         if(begin >= end) 30                 return; 31         int left = begin, right = end; 32         int pivot_value = a[left]; 33         while(left < right) 34         { 35                 if(a[left+1] < pivot_value) 36                 { 37                         a[left] = a[left+1]; 38                         left++; 39                 } 40                 else if(a[left+1] >= pivot_value) 41                 { 42                         std::swap(a[left+1], a[right]); // std::swap() 43                         right--; 44                 } 45         } 46         a[left] = pivot_value; 47         quickSort(a, begin, left-1);    // 递归 48         quickSort(a, left+1, end); 49 }

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