排序（2）——插入/希尔/选择/快速排序及优化

"Sort.h"

<strong><span style="font-size:18px;">#pragma once#include <iostream>using namespace std;#include <assert.h>#include <stack>void InsertSort(int* arr,size_t size)//直接插入排序{assert(arr);for (int i = 1;i < size;i++){int j = i-1;int tmp = arr[i];while (arr[j] > tmp && j >= 0){arr[j + 1] = arr[j];j--;}arr[j+1] = tmp;}}void SellSort(int* arr,size_t size)//希尔排序{assert(arr);int k = size;while (k > 1){k = k / 3 + 1;for (int i = k; i < size;i ++){int tmp = arr[i];int j = i - k;while (arr[j] > tmp && j >= 0){arr[j + k] = arr[j];j -= k;}arr[j + k] = tmp;}}}void SelectSort(int* arr,size_t size)//选择排序{assert(arr);for (int i = 0;i < size;i++){int min = i;for (int j = i+1;j < size;j++){if (arr[j] < arr[min]){min = j;}}//arr[i] = arr[min];//注意，这里是交换，不是赋值，很容易在这一步写错，写错了程序就会出现大错误swap(arr[i],arr[min]);}}void SelectSort_OP(int* arr,size_t size)//选择排序的优化{assert(arr);int left = 0;int right = size - 1;while (left < right){int MinIndex = left;int MaxIndex = right;for (int i = left;i <= right;i++){if (arr[i] < arr[MinIndex]){MinIndex = i;}if (arr[i] > arr[MaxIndex]){MaxIndex = i;}}swap(arr[left],arr[MinIndex]);if (MaxIndex == left)//处理当数组出现9 1 2 3 4 0的情况{MaxIndex = MinIndex;}swap(arr[right],arr[MaxIndex]);left++;right--;}}int PartSort(int* arr,int left,int right)//快速排序{assert(arr);int k = arr[right];int begin = left;int end = right;while (begin < end){while (begin < end && arr[begin] <= k)//左边找大{begin++;}while (begin < end && arr[end] >= k)//右边找小{end--;}if (begin < end){swap(arr[begin],arr[end]);}}swap(arr[begin],arr[right]);return begin;}void QuickSort(int* arr,int left,int right)//快速排序（递归实现）{assert(arr);if (left >= right){return;}int div = PartSort(arr,left,right);QuickSort(arr,left,div-1);QuickSort(arr,div+1,right);}void QuickSort_NonR(int* arr,int left,int right)//快速排序（非递归实现）{assert(arr);stack<int> _stack;_stack.push(right);_stack.push(left);while (_stack.empty() == false){int begin = _stack.top();_stack.pop();int end = _stack.top();_stack.pop();int div = PartSort(arr,begin,end);if (begin < div-1){_stack.push(div-1);_stack.push(begin);}if (div+1 < end){_stack.push(end);_stack.push(div+1);}}}</span></strong>

 

test.cpp

<strong><span style="font-size:18px;">#define _CRT_SECURE_NO_WARNINGS 1#include "Sort.h"void test1()//InsertSort{int arr[] = {1,4,3,8,2,9,8,4,6};int size = sizeof(arr)/sizeof(arr[0]);InsertSort(arr,size);for (int i = 0;i < size;i++){cout<<arr[i]<<" ";}cout<<endl;}void test2()//SellSort{int arr[] = {6,7,8,9,0,1,2,6,4,5};int size = sizeof(arr)/sizeof(arr[0]);SellSort(arr,size);for (int i = 0;i < size;i++){cout<<arr[i]<<" ";}cout<<endl;}void test3()//SelectSort{int arr[] = {6,5,1,7,2,9,1,4,6};//int arr[] = {6,5,1,7,2,9,3,4,8};int size = sizeof(arr)/sizeof(arr[0]);//SelectSort(arr,size);SelectSort_OP(arr,size);for (int i = 0;i < size;i++){cout<<arr[i]<<" ";}cout<<endl;}void test4()//QuickSort  QuickSort_NonR{int arr[] = {1,4,3,8,2,2,8,2,6};//int arr[] = {4,1};int size = sizeof(arr)/sizeof(arr[0]);//QuickSort(arr,0,8);//QuickSort(arr,0,1);QuickSort_NonR(arr,0,8);for (int i = 0;i < size;i++){cout<<arr[i]<<" ";}cout<<endl;}int main(){//test1();//test2();//test3();test4();system("pause");return 0;}</span></strong>