#include <bits/stdc++.h>
using namespace std;

struct Node {
  Node* left = NULL;
  Node* right = NULL;
  int val;
};

map<int, queue<int>> mp;

int minLevel = INT_MAX;
int maxLevel = INT_MIN;

void recurBST(Node* root, int hlevel) {
  if (root == NULL) return;
  
  minLevel = min(hlevel, minLevel);
  maxLevel = max(hlevel, maxLevel);
  
  recurBST(root->left, hlevel-1);
  mp[hlevel].push(root->val);
  recurBST(root->right, hlevel + 1);
}

Node* createNode(int val) {
  Node* node = new Node();
  node->val = val;
  return node;
}


int main() 
{
  Node* root = new Node();
  root->val = 2;
  
 root->left = createNode(3);
 root->right = createNode(4);
 root->right->left = createNode(7);
 root->right->right = createNode(8);
 
 root->left->left = createNode(6);
 
 root->left->left->right = createNode(10);
 root->left->left->right->left = createNode(15);
root->left->left->right->left->left = createNode(16);
 
root->left->left->left = createNode(9);
root->left->left->right->left->left->left = createNode(17);
 
  
  
 
 
 
  recurBST(root, 0);
  for (int i = minLevel; i <= maxLevel; i++) {
    cout<<mp[i].front()<<" ";
  }
  
  return 0;
}




// Question 1

// Top view of Binary tree

//               2
        
//         /        \
//       3              4
//     /    \         /   \
//     6      5        7     8
//     /  \  /  \    /   \    
//   9   10 11   12  13  14  
//     /
//   15
// /
// 16


// in-order -> -4 -3 -2 -1 0 1 
// 

// [-4] : [16]
// [-3]: [9 15]
// [-2]: 

// O(N)
// O(N)

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#include <iostream>
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using namespace std;

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    string name;
    cout << "Enter name:";
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    cout << "Hello " << name;
    return 0;
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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
}