leetcode-hot100 2.合并二叉树 (cpp)

图片来自leetcode 截图

//树的先序遍历，分左右，先做操作，再递归
class Solution {
public:
	TreeNode* mergeTrees(TreeNode* t1, TreeNode* t2) {
		if (t1 == NULL)
			return t2;
		if (t2 == NULL)
			return t1;

		t1->val = t1->val + t2->val;

		t1->left = mergeTrees(t1->left, t2->left);
		t1->right = mergeTrees(t1->right, t2->right);
		return t1;
	}
};