快速排序(修正)

今天又重新写了一次快排，发现之前写的有问题

 

 

 

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72

#include <iostream> using namespace std; static int count=0; int find(int arr[],int left,int right) {       int i=left,j=right-1;     int temp=i;     int t=arr[temp];     while(i<=j)     {         while(i<=j&&arr[j]>=t)           {             j--;           }           if(i<=j&&arr[j]<t)           {             arr[temp]=arr[j];             arr[j]=t;             temp=j;             j--;           }           while(i<=j&&arr[i]<=t)          {             i++;          }          if(i<=j&&arr[i]>t)          {             arr[temp]=arr[i];             arr[i]=t;             temp=i;             i++;          }           }      count++;      cout<<count<<":";      for(int i=left;i<right;i++)         cout<<arr[i]<<"   ";         cout<<endl;        return temp;   } void quickSort(int arr[],int left,int right) {     if(left>=right)     return;     int temp=find(arr,left,right);     quickSort(arr,left,temp);     quickSort(arr,temp+1,right);   }   int main() {     int arr[]={3,-1,45,0,21,9,8,7,32};     cout<<"before sort:"<<endl;     for(int i=0;i<9;i++)        cout<<arr[i]<<"  ";        cout<<endl;      quickSort(arr,0,9);      cout<<         cout<<"after sort:"<<endl;         for(int i=0;i<9;i++)        cout<<arr[i]<<"   ";        cout<<endl;       return 0; }

这个应该没问题，在确定一个分界数时一定是while（i<=j）,不然会出错。