【leetcode】 Merge Two Binary Trees

二叉树合并算法

最新推荐文章于 2022-03-21 16:50:58 发布

原创最新推荐文章于 2022-03-21 16:50:58 发布 · 500 阅读

0 ·

CC 4.0 BY-SA版权

leetcode 专栏收录该内容

71 篇文章

订阅专栏

本文介绍了一种合并两棵二叉树的算法实现。通过递归方式，将两棵树对应节点的值相加，并合并左右子树。文章提供了两种版本的代码实现，包括直接修改原树和创建新树的方法。

效率很（最）低但是一次ac了

// 617. Merge Two Binary Trees 
TreeNode* mergeTrees(TreeNode* t1, TreeNode* t2) {
	if (t1 != NULL && t2 != NULL)
	{
		t1->val = t1->val + t2->val;
		t1->left = mergeTrees(t1->left, t2->left);
		t1->right = mergeTrees(t1->right, t2->right);
		return t1;
	}
	if (t1 != NULL && t2 == NULL)
	{
		t1->left = mergeTrees(t1->left, NULL);
		t1->right = mergeTrees(t1->right, NULL);
		return t1;
	}
	if (t2 != NULL && t1 == NULL)
	{
		t2->left = mergeTrees(t2->left, NULL);
		t2->right = mergeTrees(t2->right, NULL);
		return t2;
	}
	if (t1 == NULL && t2 == NULL)
	{
		return NULL;
	}
}

重构版本：

TreeNode* mergeTrees(TreeNode* t1, TreeNode* t2) {
        if ( t1 && t2 ) {
            TreeNode * root = new TreeNode(t1->val + t2->val);
            root->left = mergeTrees(t1->left, t2->left);
            root->right = mergeTrees(t1->right, t2->right);
            return root;
        } else {
            return t1 ? t1 : t2;
        }
    }