C++ Programs, Projects & Examples With Code

Day 1: Structure of a C++ Program – Learn C++ Programming

2026-03-05T11:46:00.000-08:00

Day 1: Structure of a C++ Program

Welcome to Day 1 of our **C++ programming series**! Today we will learn the **basic structure of a C++ program**, which is essential before writing any C++ code. Understanding this structure helps you organize your code and ensures it compiles correctly.

1. Basic Structure

A simple C++ program consists of the following parts:

Headers: Libraries included for extra functionality.
Main function: The entry point of every C++ program.
Statements: Instructions executed in sequence.
Return statement: Indicates the program finished successfully.

2. Example Program

#include <iostream>  // Include standard input/output library

int main() {
    std::cout << "Hello, World!" << std::endl; // Output message
    return 0; // End of program
}

3. Explanation

#include <iostream> – Includes the standard library for input/output.
int main() – Main function where execution starts.
std::cout << "Hello, World!" << std::endl; – Prints text to the console.
return 0; – Signals successful completion.

4. Video Tutorial

Watch this video to see a detailed explanation and live coding:

5. Key Takeaways

Every C++ program needs a main() function.
Include necessary headers to access libraries.
Use return 0; to indicate successful execution.
Statements inside main() are executed sequentially.

✅ Tip: Practice writing multiple small programs to get comfortable with the program structure.

CS304 - Object Oriented Programming Fall 2018 Assignment No. 01 Solution

2018-12-09T14:00:00.002-08:00

Problem Statement:

We have the following part of class diagram showing aggregation relationship:

You are required to implement above class diagram (complete program) in C++ with all data members, constructors, member functions and concept (aggregation) given in the class diagram/table

Class Name	Functions
Grocery Home	-Default constructor
Fruit Store	-Default constructor
Fruit Store	-Default constructor
Grocery Store	-Default constructor
Dairy Store	-Default constructor
Apple	-Default constructor
Grapes	-Default constructor
Guava	-Default constructor
Tetra Milk	-Default constructor
Whitener	-Default constructor
Cream	-Default constructor
Cooking Oil	-Default constructor
Rice	-Default constructor
Flour	-Default constructor

Solution or Download.cpp

#include <iostream>
using namespace std;
class Apple{
 public:
 Apple(){
  cout<<"Apple Constructor called\n";
 }
};
class Grapes{
 public:
 Grapes(){
  cout<<"Grapes Constructor called\n";
 }
};
class Guava{
 public:
 Guava(){
  cout<<"Guava Constructor called\n";
 }
};
class FruitStore{
 Apple a;
 Grapes g;
 Guava gv;
 public:
  FruitStore(){
   cout<<"\nFruit Store Constructor called\n\n";
   
  }
};
class CookingOil{
 public:
 CookingOil(){
  cout<<"Cooking Oil Constructor called\n";
 }
}; 
class Rice{
 public:
 Rice(){
  cout<<"Rice Constructor called\n";
 }
};
class Flour{
 public:
 Flour(){
  cout<<"Flour Constructor called\n";
 }
};
class GroceryStore{
 CookingOil c;
 Rice r;
 Flour f;
 public:
 GroceryStore(){
 cout<<"\nGrocery Store Constructor called\n\n";
 
 }
};
class TetraMilk{
 public:
 TetraMilk(){
  cout<<"Tetra Milk Constructor called\n";
 }
};
class Whitener{
 public:
 Whitener(){
  cout<<"Whitener Constructor called\n";
 }
};
class Cream{
 public:
 Cream(){
  cout<<"Cream Constructor called\n";
 }
};
class DairyStore{
 TetraMilk t;
 Whitener w;
 Cream c;
 public:
 DairyStore(){
  cout<<"\nDairy Store Constructor called\n\n";
  
 }
};
class GroceryHome{
 FruitStore f;
 GroceryStore g;
 DairyStore d;
 public:
  GroceryHome(){
   cout<<"Grocery Home Constructor called\n\n";
  }
};

main(){
 GroceryHome g;
 
}

CS301 Assignment No 01 Solution Fall 2018

2018-12-09T13:38:00.000-08:00

Binary Search tree is the most efficient data structure for solving different problems. Construction of BST (Binary Search Tree) depends on the order in which data is inserted into the tree. For building a Binary Search Tree, data should be inserted into a tree in a way that nodes with smaller data values appears on left side and larger node values appears on right side of the root node.

Write a menu based system program in C++ that will allow you to:

Enter Employee data in BST	buildBST()
Post order traversal of all the Employee data	postOrder()
Show data in ascending order	asscendingOrder()

Take the following attributes of an Employee from the user:

empId, empNname, empSalary

You have to implement the above scenario using BST on the basis of Employee Id. i.e. if the Id of the Employee is lesser than the root node then enter the next Employee data in the left child otherwise in right child.

Note:

BST will implement using Linked List.
Program will not allow entering duplicate employee id.
Design the program in a way that the user will be able to enter maximum 10 records.
Take empId, empName, empSalary from the user. At least 4 students record should be already entered (hard coded records).

You will use following already entered Employees data (hard coded records).

Emp Id	Name	EmpSalary
32	Raza	3000
56	Sajjad	25000
93	Rabia	19230
5	Sehar	24000
10	Ali	22200

Solution Guidelines:

You will use buildBST() method to build Binary Search Tree from the above given data.
Use the ascendingOredr() method to show the output in ascending order. With respect to empId.
Use postOrder() method to traverse the records in post-order.

Sample output 1:

Solution: Download.cpp

#include<iostream>
#include<conio.h>
#include<string>
#include<cstring>

using namespace std;

struct Node
{
int empId;
char* empName;
double empSalary;

Node* left;
Node* right;
};
Node* buildBST(Node* root, int i,int id, char* name, double salary)
{

if(root== NULL)
{
Node* newNode = new Node();
newNode->empId = id;
newNode->empName = name;
newNode->empSalary = salary;
newNode->left = newNode->right = NULL;
return newNode;
}
if(root->empId == id) // if the element already exists dont need to enter it again...
{
return root;
}
else if(id <= root->empId)
{
root->left = buildBST(root->left, i, id, name, salary);
}
else
{
root->right = buildBST(root->right, i, id, name, salary);
}
}
void ascendingOrder(Node* root)
{
if(root==NULL)
{
return;
}
ascendingOrder(root->left);
cout<<endl<<root->empId<<"\t"<<root->empName<<"\t"<<root->empSalary<<endl;
ascendingOrder(root->right);
}
void postOrder(Node* root)
{
if(root==NULL)
{
return;
}
postOrder(root->left);
postOrder(root->right);
cout<<root->empId<<"\t"<<root->empName<<"\t"<<root->empSalary<<endl;
}

main()
{

int id[]= {32,56,93,5,10};
char* name[]= {"Raza","Sajid","Rabia","Sehar","Ali"};
double salary[]= {3000, 25000, 19230, 24000, 22200};
int c;
int x = (sizeof(id)/sizeof(*id)); // getting the elements of the array, in that case '5'
Node* root = NULL;
char string[20]; // for new entry a temporary array for getting name....

// loop for entering of the given table in the tree...
for(int i=0; i<x; i++)
{
root = buildBST(root, i, id[i], name[i], salary[i]);
}

// conditions...
s:
cout<<endl<<"Press 1 to Enter Data \n";
cout<<"Press 2 to see the Records in Ascending Order \n";
cout<<"Press 3 to see the Records in Post Order \n";
cout<<"Press 4 to Exit\n ";
cin>>c;
switch(c)
{
case 1:
{
r:
cout<<endl<<"Enter Employee ID : ";
cin>>id[x];
cout<<endl<<"Enter Employee Salary : ";
cin>>salary[x];
cout<<endl<<"Enter Employee Name : ";
cin>>string;
// checking redundancy (duplication) for ID...
for(int i=0; i<x; i++)
{
if(id[x] == id[i])
{
cout<<endl<<"Record Already Exists...";
goto r;
}
}
// assigning name a dynamic memory....
name[x] = new char[strlen(string)+1];
strcpy(name[x], string);

// again update the tree...
for(int i=0; i<(x+1); i++)
{
root = buildBST(root, i, id[i], name[i], salary[i]);
}
break;
}
case 2:
cout<<"Ascending Order: \n";
ascendingOrder(root);
break;
case 3:
cout<<"Post Order: \n";
postOrder(root);
break;
case 4:
break;
default:
cout<<"\nWrong Input.";
break;
}
char ch;
y:
cout<<endl<<"DO YOU WANT TO DO SOMETHING ELSE...\nYES = y \t NO = n";
ch = getch();
if(ch=='y')
{
goto s;
}
else if(ch=='n')
{
cout<<"\nBye!";
}
else
{
cout<<endl<<"\nWrong input.";
goto y;
}
}