Learn Algorithms from LeetCode-120 (0547. Number of Provinces)

Categories: Graph/Union Find, Level: Medium

Chih-Yu Lin
5 min readJun 6, 2023


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There are n cities. Some of them are connected, while some are not. If city a is connected directly with city b, and city b is connected directly with city c, then city a is connected indirectly with city c.

A province is a group of directly or indirectly connected cities and no other cities outside of the group.

You are given an n x n matrix isConnected where isConnected[i][j] = 1 if the ith city…



Chih-Yu Lin

LeetCode、Python、Java、Android;第11屆iT邦幫忙鐵人賽Software Development組優選(從LeetCode學演算法);HiSKIO特約講師;課程優惠: https://bit.ly/lc2022all ;合作請洽: learnwithdesolve@gmail.com