快速排序

 #include <iostream>
  
  using namespace std;
  
  void quicksort(int *datapointer,int low,int high)
  {
  
      if(low>=high)
          return;
     int i = low;
     int j = high;
     int key = datapointer[low];
 
     while(i<j)
     {
 
         while(datapointer[j]>=key&&i<j)
             j--;
         datapointer[i] = datapointer[j];
         //cout<<"hello"<<endl;
         while(datapointer[i]<=key&&i<j)
             i++;
         datapointer[j] = datapointer[i];
     }
     datapointer[i] = key;
     quicksort(datapointer,low,i-1);
     quicksort(datapointer,i+1,high);
 }
 
 int main()
 {
     int *datapointer,num;
     cin>>num;
     datapointer = new int[num+1];
     for(int i = 1;i <= num; i++)
         cin>>datapointer[i];
 
 
 
     quicksort(datapointer,1,num);
     for(i = 1;i <= num; i++)
         cout<<datapointer[i]<<" ";                                              
     cout<<endl;                                                                 
     return 0;
 }