#include <iostream>
#include<vector>
using namespace std;
template<typename T>
TreeNode<int>* takeInputLevelWise(){
  int rootData;
  cout<<"Enter root Data"<<endl;
  cin>>rootData;
  TreeNode<int> * root = new TreeNode<int>(rootData);
  queue<TreeNode<int>*> pendingNodes;
  pendingNodes.push(root);
  while(pendingNodes.size()!=0){
    TreeNode<int>* front = pendingNodes.front();
    pendingNodes.pop();
    int numChild;
    cout<<"Enter num of children of "<<front->data<<endl;
    cin>>numChild
    for(int i = 0;i<numChild;i++){
      int childData;
      cout<<"Enter "<<i<<"th child of "<<front->data<<endl;
      cin>>childData;
      TreeNode<int>* child = new TreeNode<int>(childData);
      pendingNodes.push(child);
      front->children.push_back(child);
    }
  }
  return root
}
class TreeNode{
  public:
  T data;
  vector<TreeNode*> children;
  TreeNode(T data){
    this->data = data;
  }
  
};
TreeNode<int>* takeInput(){
  int rootData;
  cout<<"Enter Data"<<endl;
  cin>>rootData;
  TreeNode<int>*root = new TreeNode<int>(rootData);
  int numChild;
  cout<<"Enter num of child"<<endl;
  cin>>numChild;
  for(int i = 0;i<numChild;i++){
    TreeNode<int>* child = takeInput();
    root->children.push_back(child);
  }
  return root;
}
void printTree(TreeNode<int>*root){
  cout<<root->data<<":";
  for(int i = 0;i<root->children.size();i++){
    cout<<root->children[i]->data<<",";
  }
  cout<<endl;
  for(int i= 0;i<root->children.size();i++){
    printTree(root->children[i]);
    
  }
}

int main() 
{
    // TreeNode<int>*root = new TreeNode<int>(1);
    // TreeNode<int>*child1 = new TreeNode<int>(2);
    // TreeNode<int>*child2 = new TreeNode<int>(3);
    // TreeNode<int>*child3 = new TreeNode<int>(4);
    // root->children.push_back(child1);
    // root->children.push_back(child2);
    // child1->children.push_back(child3);
    TreeNode<int>*root = takeInput();
    printTree(root);
    return 0;
}
by

C++ Online Compiler

Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!

Read inputs from stdin

OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}