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Time: 30 minutes The question is divided into two parts to be solved, search and delete The search part is to find the node. You can find the required node according to the properties of the binary …
#669. Pruning a binary search tree Release Date: March 11, 2021 Time: 20 minutes Similar to the previous question, most of them are divided into situations where the parent node is in the interval and …
Time: Not done The main reason I didn’t make it was that I kept thinking about how to use a stack. When I looked at the answer to the stack later, I found that recursion was the simplest. recursion …
Time: 25 minutes The main idea is to use the stack. The difference from the ordinary level-order traversal is that the stack is cleared every time var connect = function(root) { if (!root) return null …
Time: I copied the answers and finished it. It is easy to see that the idea is to use recursion, but the coding is the real problem. What we need to return is the root node, but the recursion is from …
Time: 30 minutes Serialization is simple and can be solved using BFS Deserialization requires the use of the properties of a binary tree, that is, the child nodes of the i-th node are (i + 1) * 2 - 1 …
Time: 25 minutes In fact, this is a relatively common DFS type question. The reason why it took so long is because there was a problem in judging the boundary value. When starting from the root, since …
Time: 10 minutes The question is to find the path from the root node to the child nodes whose sum is equal to the target value. It is easy to think of using DFS. The path can be passed as a parameter. …
When traversing a binary tree in front, middle, or post-order, we use a stack to simplify operations. This is because they are all recursive structures of DFS, which means processing from bottom to …
