Factor Tree of a given Number

2

Factor Tree is an intuitive method to understand factors of a number. It shows how all the factors are been derived from the number. It is a special diagram where you find the factors of a number, then the factors of those numbers, etc until you can’t factor anymore. The ends are all the prime factors of the original number.

Example:

Input : v = 48
Output : Root of below tree
   48
   /\
  2  24
     /\
    2  12
       /\
      2  6
         /\
        2  3

The factor tree is created recursively. A binary tree is used.

  1. We start with a number and find the minimum divisor possible.
  2. Then, we divide the parent number by the minimum divisor.
  3. We store both the divisor and quotient as two children of the parent number.
  4. Both the children are sent into function recursively.
  5. If a divisor less than half the number is not found, two children are stored as NULL.
// C++ progrm to construct Factor Tree for
// a given number
#include<bits/stdc++.h>
using namespace std;

// Tree node
struct Node
{
    struct Node *left, *right;
    int key;
};

// Utility function to create a new tree Node
Node* newNode(int key)
{
    Node* temp = new Node;
    temp->key = key;
    temp->left = temp->right = NULL;
    return temp;
}

// Constructs factor tree for given value and stores
// root of tree at given reference.
void createFactorTree(struct Node **node_ref, int v)
{
    (*node_ref) = newNode(v);

    // the number is factorized
    for (int i = 2 ; i < v/2 ; i++)
    {
        if (v % i != 0)
          continue;

        // If we found a factor, we construct left
        // and right subtrees and return. Since we
        // traverse factors starting from smaller
        // to greater, left child will always have
        // smaller factor
        createFactorTree(&((*node_ref)->left), i);
        createFactorTree(&((*node_ref)->right), v/i);
        return;
    }
}

// Iterative method to find height of Bianry Tree
void printLevelOrder(Node *root)
{
    // Base Case
    if (root == NULL)  return;

    queue<Node *> q;
    q.push(root);

    while (q.empty() == false)
    {
        // Print front of queue and remove
        // it from queue
        Node *node = q.front();
        cout << node->key << " ";
        q.pop();
        if (node->left != NULL)
            q.push(node->left);
        if (node->right != NULL)
            q.push(node->right);
    }
}

// driver program
int main()
{
    int val = 48;// sample value
    struct Node *root = NULL;
    createFactorTree(&root, val);
    cout << "Level order traversal of "
            "constructed factor tree";
    printLevelOrder(root);
    return 0;
}

Output:

Level order traversal of constructed factor tree
48 2 24 2 12 2 6 2 3 

This article is contributed by Suprotik Dey. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

GATE CS Corner    Company Wise Coding Practice

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.

Recommended Posts:



2 Average Difficulty : 2/5.0
Based on 1 vote(s)










Writing code in comment? Please use ide.geeksforgeeks.org, generate link and share the link here.