261 - Graph Valid Tree
This problem asks you to determine if a given undirected graph is a valid tree.
A valid tree is an undirected graph in which any two vertices are connected by exactly one path.
It's typically solved using Union-Find (Disjoint Set) or Depth-First Search (DFS) algorithms.
323 - Number of Connected Components in an Undirected Graph
This problem asks you to count the number of connected components in an undirected graph.
It can be solved using either Depth-First Search (DFS), Breadth-First Search (BFS), or Union-Find algorithms.
721 - Accounts Merge
This problem involves merging email accounts based on common email addresses.
It's typically solved using a Union-Find (Disjoint Set) data structure or Depth-First Search (DFS).
547 - Number of Provinces
This problem asks you to find the number of provinces (connected components) in a graph represented by an adjacency matrix.
It can be solved using Depth-First Search (DFS), Breadth-First Search (BFS), or Union-Find algorithms.
305 - Number of Islands II
This is a dynamic version of the Number of Islands problem.
It involves adding land to a 2D grid and counting the number of islands after each addition.
It's typically solved using a Union-Find (Disjoint Set) data structure.
在Amazon和Meta的面试中Union Find并查集时候考到的,除了卡马网的三道题建议增加一些leetcode上的板子题作为训练。
以下是我做了很多之后整理出来比较好的题