Tree/MergeBinaryTrees.cpp

// Problem: https://leetcode.com/problems/merge-two-binary-trees/
// 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 MergeBinaryTrees {
public:
	TreeNode* mergeTrees(TreeNode* root1, TreeNode* root2) {
		if (root1 == nullptr) return root2;
		if (root2 == nullptr) return root1;
		TreeNode* newNode = new TreeNode(root1->val + root2->val);
		newNode->left = mergeTrees(root1->left, root2->left);
		newNode->right = mergeTrees(root1->right, root2->right);
		return newNode;
	}
};