Quick Sort c++，int main()中的代码实现

Question

我尝试开发c++程序，Quick Sort。在 int main() 中，第一个菜单是：

1. 100 elements
2. 500 elements
3. 1000 elements.
4. Quit

用户选择或输入1/2/3后，用户需要选择：

3. Pivot: First Element
4. Pivot: Random element.

问题是我的代码太长了，因为我没有让它变得简单，而且我不知道该怎么做。我用同样的方法。

用于对 100 个元素进行排序：

Load data>>print unsorted>>quicksort>>print sorted. This is for pivot first element.

Then for pivot random element, I need to load again the same 100 elements data and do the same again,Load data>>print unsorted>>quicksort>>print sorted.

同样适用于 500 和 1000 个元素。看到我这样的代码好累

int main(){  

 int ch,ch2;
 while(1)
{
   cout<<endl<<endl; 
   cout << "\n QUICK SORT(RANDOM NUMBER)\n";     
   cout << " ---------------------------------\n";
   cout << "\n 1.100 elements\n 2.500 elements\n 3.1000 elements\n 4.Quit\n";
   cout<<  " ---------------------------------"<<endl;
   cout<<" Enter your choice : ";
   cin>>ch;
   cout<<endl;
   switch(ch)
   {

       case 1 : cout << "\n 3.Pivot : First Element \n 4.Pivot: Random element\n";
               cout<<  " ---------------------------------"<<endl;
               cout<<" Enter your choice : ";
               cin>>ch2;
               cout<<endl;
              if(ch2==3){      
                                    ifstream file;
                                    file.open("100.txt");
                                    if(!file) {
                                        cout<<" Error opening file. " << endl;
                                    }
                                    int input1[100];

                                       for(int i = 0; i < 100; i++)
                                     {  file>>input1[i];
                                     }                              
                                       file.close(); 

                                            cout << " UNSORTED DATA (100 elements) \n";
                                            cout<<  " ------------------------------------------------"<<endl;
                                            print(input1,99);        


                                            //Quick sort Pivot: first element                                  
                                            cout << " SORTED DATA (100 elements) Pivot: First Element: \n";
                                            cout<<  " ------------------------------------------------"<<endl;
                                            quicksort1(input1, 0, 99);                    
                                            cout<<endl; 
                                            print(input1,99);
                                            cout << " Number of comparison: \n";
                                            cout << " Number of moves required: \n";
                                            cout<<endl; 
                                            break;
                                            }
         else{      
              ifstream file2;
                file2.open("100.txt");
                if(!file2) {
                    cout<<" Error opening file. " << endl;
                }
                int input2[100];

                   for(int i = 0; i < 100; i++)
                 {  file2>>input2[i];
                 }                              
                   file2.close(); 
                   cout << " UNSORTED DATA (100 elements) \n";
                                            cout<<  " ------------------------------------------------"<<endl;
                                            print(input2,99);           

                //Quick sort Pivot: random element                    
                cout << " SORTED DATA (100 elements) Pivot: Random Element: \n";
                cout << " ------------------------------------------------"<<endl;
                 print(input2,99);
               quicksort2(input2, 0, 99);
                cout<<endl;
                print(input2,99);
                cout << " Number of comparison: \n";
                cout << " Number of moves required: \n";

                cin.get();
                //if windows suddenly close
               break;         
               }                              

                   break;
        case 2 :cout << "\n 3.Pivot : First Element \n 4.Pivot: Random element\n";
               cout<<  " ---------------------------------"<<endl;
               cout<<" Enter your choice : ";
               cin>>ch2;
               cout<<endl;
              if(ch2==3){      
                                    ifstream file;
                                    file.open("500.txt");
                                    if(!file) {
                                        cout<<" Error opening file. " << endl;
                                    }
                                    int input1[500];

                                       for(int i = 0; i < 500; i++)
                                     {  file>>input1[i];
                                     }                              
                                       file.close(); 

                                            cout << " UNSORTED DATA (500 elements) \n";
                                            cout<<  " ------------------------------------------------"<<endl;
                                            print(input1,499);        


                                            //Quick sort Pivot: first element                                  
                                            cout << " SORTED DATA (500 elements) Pivot: First Element: \n";
                                            cout<<  " ------------------------------------------------"<<endl;
                                            quicksort1(input1, 0, 499);                    
                                            cout<<endl; 
                                            print(input1,499);
                                            cout << " Number of comparison: \n";
                                            cout << " Number of moves required: \n";
                                            cout<<endl; 
                                            break;
                                            }
         else{      
              ifstream file2;
                file2.open("500.txt");
                if(!file2) {
                    cout<<" Error opening file. " << endl;
                }
                int input2[500];

                   for(int i = 0; i < 500; i++)
                 {  file2>>input2[i];
                 }                              
                   file2.close();  
                   cout << " UNSORTED DATA (500 elements) \n";
                                            cout<<  " ------------------------------------------------"<<endl;
                                            print(input2,499);          

                //Quick sort Pivot: random element                    
                cout << " SORTED DATA (100 elements) Pivot: Random Element: \n";
                cout << " ------------------------------------------------"<<endl;
                 print(input2,499);
               quicksort2(input2, 0, 499);
                cout<<endl;
                print(input2,499);
                cout << " Number of comparison: \n";
                cout << " Number of moves required: \n";

                cin.get();
                //if windows suddenly close
               break;         
               }                              

                   break;
        case 3 :
               break;
        case 4 :
               break;            
  }

Answer 1

我建议您先采用 DRY 方法，首先考虑 2 个变量：

1- 输入数

2- 枢轴选择

   cout<<endl<<endl; 
   cout << "\n QUICK SORT(RANDOM NUMBER)\n";     
   cout << " ---------------------------------\n";
   cout << "\n 1.100 elements\n 2.500 elements\n 3.1000 elements\n 4.Quit\n";
   cout<<  " ---------------------------------"<<endl;
   cout<<" Enter your choice : ";
   cin>>ch;
   cout<<endl;


   cout << "\n 3.Pivot : First Element \n 4.Pivot: Random element\n";
   cout<<  " ---------------------------------"<<endl;
   cout<<" Enter your choice : ";
   cin>>ch2;
   cout<<endl;

   string inputSize;
   switch(ch)
   {
   case 1: inputSize="100";
    ...
   }
   string pivotSelection;
   switch(ch2)
   {
   case 1: pivotSelection="FirstElement";
    ...
   }

然后重写您的代码块以使用这些变量而不是对所有内容进行硬编码。例如，您可以 file.open( inputSize + ".txt");

而不是 file.open("500.txt");

但是，使用此方法时，您必须注意，在 C++ 中，您不能创建可变大小的堆栈分配数组。例如，您需要 int * inputs = malloc(sizeof(int) * sizeOfInput);

而不是 int inputs[sizeOfInput];

Quick Sort c++，int main()中的代码实现

Quick Sort c++, code implementation in int main()

c++

quicksort