DAY7P1.md

Diameter of Binary Tree

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• Question:

Given the root of a binary tree, return the length of the diameter of the tree.

The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root.

The length of a path between two nodes is represented by the number of edges between them.

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• Example:

Input: root = [1,2,3,4,5]

Output: 3

Explanation: 3 is the length of the path [4,2,1,3] or [5,2,1,3].

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• Solution:

Code :

class Solution {
    int ans=0;
    public int diameterOfBinaryTree(TreeNode root) {
        if(root==null )return 0;
        height(root);
        return ans;
    }
    
    public int height(TreeNode root){
        //if root==null height==0
        if(root==null)return -1;
        
        int L=height(root.left);
        int R=height(root.right);
        //ans signfies(no. of nodes farthest apart) or the DIAMETER
        ans=Math.max(ans,L+R+2);
        //height of the tree is max of LST & RST +1
        return 1+Math.max(L,R);
    }
}