Persistent Interview Experience C++

Round 1: Online test for 60 minutes. Test consists of questions related to C++ and analytical problems.

Round 2: Technical interview

• What are the various OOPs concepts in C++ ?
  Answer : OOPs in C++
• Difference between encapsulation and abstraction?
• What are the C++ access specifiers?
  Answer : Check Here
• How to call private function from child class ?
  Answer : Using Friend Function
• What is the Diamond Problem in C++ ?
  Answer : Check here and here
• What is Polymorphism and types of it ?
• Where and why use run-time Polymorphism ?
• Why use parameters int argc, char *argv[] in main function ?
  Answer : Check here
• 
  

  #include<iostream>
  using namespace std;
  #define main xyz
  int main(int argc,char *argv[])
  {
       main();
       return 0;
  } 
  int xyz()
  {
      cout << "hi";
      return 0;
  }

  Will above program be compiled ? What will be the output ?
• 
  

  struct s
  {
      char c;
      int i;
  };

  What is the size of the structure ?
  Answer : 8 (Because of padding). Read here
• Write C++ program to print below output.

        1      
       2 2     
      3 3 3    
     4 4 4 4   
    5 5 5 5 5  
   6 6 6 6 6 6 

  The number of rows can be any.
  Answer :
  

  #include <iostream>
  
  using namespace std;
  
  int main()
  {
     int rows;int n;string space = " ";
     cout << "Enter Number of rows" << endl; 
     cin >> rows;
     
     cout << "rows : "<< rows << endl;
     for (int t = 1; t <= rows; t++)
     {
         for (int i = t; i <= rows; i++)
         {
             cout << space;
         }
          n = t; 
         for(int j = 1; j <= t; j++)
         {
             cout << t;
             if( n > 1 )
             {
                 cout << space;
             }
             n--;
         }
         for (int k = t; k <= rows; k++)
         {
             cout << space;
         }
         cout << endl;
     }
     
     return 0;
  }