刷题617. Merge Two Binary Trees

一、题目说明

题目617. Merge Two Binary Trees，合并两个二叉树。难度是Easy！

二、我的解答

这个题目，用递归解法非常简单，同二叉树的递归遍历。

class Solution{
	public:
		TreeNode* mergeTrees(TreeNode* t1,TreeNode* t2){
			if(t1==NULL) return t2;
			if(t2==NULL) return t1;
			int cur = t1->val + t2->val;
			TreeNode* root = new TreeNode(cur);
			root->left = mergeTrees(t1->left,t2->left);
			root->right = mergeTrees(t1->right,t2->right);
			return root;
		}
};

性能如下：

Runtime: 52 ms, faster than 46.21% of C++ online submissions for Merge Two Binary Trees.
Memory Usage: 26.1 MB, less than 5.55% of C++ online submissions for Merge Two Binary Trees.

三、优化措施

非递归算法就不写了。