Implement isSameTree function to compare two trees

[aryaman0406]

PR Title Format: 100.Same Tree.cpp💡 IntuitionTo determine if two trees, $p$ and $q$, are the same, we must check two things recursively:They must have the same structure (i.e., if one node is null, the corresponding node in the other tree must also be null).Any corresponding non-null nodes must have the same value.This naturally leads to a Depth-First Search (DFS) / Preorder Traversal approach, comparing the nodes at each step of the recursion.✍️ ApproachThe solution uses recursion to traverse both trees simultaneously, comparing the nodes at each level:Base Case 1 (Both Null): If both nodes $p$ and $q$ are NULL (meaning we've reached the end of a branch simultaneously), the trees are identical up to this point. We return true.Base Case 2 (One Null or Different Value): If $p$ and $q$ are not the same in structure or value, we return false. This covers two scenarios:One node is NULL and the other is not (structural mismatch).Both are non-null, but their values (p->val and q->val) are different.Recursive Step (Same Structure and Value): If both nodes $p$ and $q$ are non-null and have the same value (p->val == q->val), we must continue the comparison for their children. The trees are the same only if the left subtrees are the same AND the right subtrees are the same. We return the logical AND of the two recursive calls:$$\text{isSameTree}(p.\text{left}, q.\text{left}) \land \text{isSameTree}(p.\text{right}, q.\text{right})$$This recursive definition perfectly captures the requirement for identical trees.Code Solution (C++)C++/**

• Definition for a binary tree node.

• struct TreeNode {

• int val;

• TreeNode *left;

• TreeNode *right;

• TreeNode() : val(0), left(nullptr), right(nullptr) {}

• TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}

• TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}

• };
  /
  class Solution {
  public:
  bool isSameTree(TreeNode p, TreeNode* q) {
  // Base Case 1: If both nodes are NULL, they are the same.
  if (!p && !q) {
  return true;
  }

   // Base Case 2: If one is NULL OR their values are different, they are NOT the same.
   if (!p || !q || p->val != q->val) {
       return false;
   }
  
   // Recursive Step: Check if both left and right subtrees are the same.
   return isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
  

  }
  };
  🔗 Related IssuesBy submitting this PR, I confirm that:[x] This is my original work not totally AI generated[x] I have tested the solution thoroughly on leetcode[x] I have maintained proper PR description format[x] This is a meaningful contribution, not spam

Summary by Sourcery

New Features:

• Add isSameTree function to compare two binary trees using recursive DFS

[sourcery-ai]

Reviewer's guide (collapsed on small PRs)

Reviewer's Guide

Introduced a recursive depth-first comparison function that checks structural and value equality of two binary trees using preorder traversal.

File-Level Changes

Change	Details	Files
Implement recursive isSameTree function with base and recursive cases	Add base case returning true when both nodes are null Add mismatch check returning false when one node is null or values differ Combine recursive calls for left and right subtrees with logical AND	Same Tree

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