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by Sumit Chourasia | Oct 07, 2020 | Category :coding | Tags : algorithm binary-tree data-structure easy leetcode tree

Diameter of Binary Tree - Tree - Easy - LeetCode

Diameter of Binary Tree - Tree - Easy - LeetCode

Given a binary tree, you need to compute 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.

Example:
Given a binary tree
          1
         / \
        2   3
       / \     
      4   5    
Return 3, which is the length of the path [4,2,1,3] or [5,2,1,3].

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

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     public int val;
 *     public TreeNode left;
 *     public TreeNode right;
 *     public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
public class Solution {
    int maxDiameter = 0;
    public int DiameterOfBinaryTree(TreeNode root) {        
        Height(root);
        return maxDiameter;
    }
    
    private int Height(TreeNode root){
        if(root==null){
            return 0;
        }
        
        int left = Height(root.left);
        int right = Height(root.right);
        maxDiameter = Math.Max(maxDiameter,left+right);
        return 1+Math.Max(left,right);
    }
}

Time Complexity: O(n)

Space Complexity: O(1)