C++实现各种基础排序（冒泡、选择、快排、插入、堆排、希尔、归并）

#include "sort.h"/*-----------------交换类排序------------------------------*///冒泡排序bool BubbleSort(int arr[],int len){if (arr == NULL){return false;}bool bDone = true;//一个标记，只有当元素交换进行后，bDone= true,如果遍历一遍，元素没有交换证明原数组已有序，则不用再进行下去for (int i = len-1; i > 0&& bDone; --i){bDone = false;for (int j = 0; j < i; ++j){if (arr[j] > arr[j+1]){int temp = arr[j];arr[j] = arr[j+1];arr[j+1] = temp;bDone = true;}}}return true;}//冒泡排序的改进版/*上面算法中，变量i只往前进一步但有时候，这个序列后面部分连续几个已经都是有序的了，那么我们就不用在一个一个往前进了EX：数组 arr[] = {1,3,2,6,7}只有3,2是无序的，当j = 1时进入交换，交换完毕后，至少从j到最后都是有序的了所以只要我们记住交换位置j就可以省去一些过程*/bool BubbleSort2(int arr[],int len){if (arr == NULL){return false;}bool bDone = true;int last = len;int i = len-1;while(i>0 && bDone){ bDone = false;for (int j = 0;j <i; ++j){if (arr[j] >arr[j+1]){int temp = arr[j];arr[j] = arr[j+1];arr[j+1] = temp;bDone = true;last = j;//记住交换位置}}i = last;}return true;}//快速排序/*快速排序的思想就是通过选择一个关键字介于“中间”的元素快速将数组分成两部分，然后分别对这两部分进行排序快排的事件复杂度为O(nlogn),当所选关键字介于数组最中间时效率最高*/int Sort(int arr[],int left,int right){if (arr == NULL){return -1;}int temp = arr[left];int low = left,high = right;while (low < high){while(low <high && arr[high]>= temp)high--;arr[low] = arr[high];while (low <high && arr[low] <= temp)low ++;arr[high] = arr[low];}arr[low] = temp;return low;}bool QSort(int arr[],int start,int end){if (arr == NULL){return false;}int mid = 0;if(start <end){mid = Sort(arr,start,end);if (mid == -1){return false;}QSort(arr,0,mid-1);QSort(arr,mid+1,end);}return false;}/*------------------------------------选择类排序--------------------------------*///简单选择排序/*如果前i-1都是有序的，在后面的元素中找到最小的元素与第i个进行交换，那么前i个都是有序的了*/bool SelectSort(int arr[],int len){if (arr == NULL){return false;}for (int i = 0; i<len-1; ++i){int k = i;for (int j = i+1; j<len; ++j){if (arr[j] <arr[k]){k = j;}}if (k!= i){int temp = arr[i];arr[i] = arr[k];arr[k] = temp;}}return true;}//堆排void AdjustHeap(int arr[],int root,int end){//调整为大根堆if (arr == NULL){return;}int t=arr[root];int  i = root*2+1;while( i <= end){if (i<end && arr[i]<arr[i+1]){i++;}if (arr[i] <= t){//原根节点是最大元素不用调整break;}else{arr[(i-1)/2] = arr[i];//将元素上调i = i*2+1;//继续寻找原根元素的合适位置}}arr[(i-1)/2] = t;}bool HeapSort(int arr[],int len){if (arr == NULL){return false;}for (int i = (len-1)/2; i>=0; --i){AdjustHeap(arr,i,len);//建堆}for (int i = len; i>0; --i){int temp = arr[0];//换元素arr[0] = arr[i];arr[i] = temp;AdjustHeap(arr,0,i-1);//重新调整堆}return true;}//归并排序/*先分而治之，然后再归并*/void Merge(int src[],int des[],int start,int mid,int end){int i = start,j = mid+1;int k = start;while(i <= mid && j<= end){if (src[i]< src[j]){des[k++] = src[i++];}elsedes[k++] = src[j++];}while (i<= mid){des[k++] = src[i++];}while( j <= end){des[k++] = src[j++];}}void MergeSort(int src[],int des[],int start,int end){if (src == NULL || des == NULL){return;}int len = (end-start)+1;         int *p = new int[len]; memset(p,0,len); if (start == end) { des[end] = src[end]; } else {        int mid = start + (end- start)/2;MergeSort(src,p,0,mid);MergeSort(src,p,mid+1,end);Merge(p,des,start,mid,end); }}/*-----------------------------------插入排序-----------------------*///直接插入排序/*找到一个不合适（顺序不对）的数，然后往前寻找到他合适的位置，将前面的元素都往后挪直到找到他的位置，插入正序效率最高，逆序效率最低  O(n^2)*/bool InsertSort(int arr[],int len){if (arr== NULL){return false;}      for(int i = 1; i<len; ++i)  {  if (arr[i] <arr[i-1])  {  int temp = arr[i];  int j = i-1;  for (; j>=0 && arr[j] >temp;--j)  {//寻找位置，并往后挪 arr[j+1] = arr[j];  }  arr[j+1] = temp;  }  }  return true;}//折半插入排序/*只有一点与直接插入不同：直接插入排序在寻找合适位置时是一个一个查找，而折半插入在查找合适位置时使用二分查找的思想查找，所以在查找这里节省了时间但是他只是在查找上节省时间，复杂度仍为O(n^2)*/bool HalfSort(int arr[],int len){if (arr == NULL){return false;}for (int i = 1; i<len; ++i){if (arr[i] <arr[i-1]){int temp = arr[i];int low = 0;int high = i;while(low <high){int mid = low+ (high-low)/2;  if (arr[mid] <temp )  {low = mid+1;  }  else  high = mid-1;}int j = 0;for ( j= i-1; j>= low; --j){arr[j+1] = arr[j];}arr[j+1] = temp;}}return true;}//希尔排序/*一次选取一个step,进行交换比较，每次缩短Step,直至Step=1，Step = 1的时候其实就是直接插入排序Shell排序就是为了减小元素据其最终位置的距离，减小移动次数*/bool ShellSort(int arr[],int len,int step){if(arr == NULL){return false;}while(step >=1){for (int i = step; i<len;++i){if (arr[i] <arr[i-step]){int temp = arr[i];int j = 0;for (j = i-step;j >=0 && arr[j] > temp; j-=step){arr[j+step] = arr[j];}arr[j+step ] =temp;}}step /=2;}}

以上排序，虽然简单，但是全是基础啊亲，笔试面试什么的一定要准备上

 

 

                                                                                                   【热爱工作，热爱生活】