Number of Connected Components
Detailed guide and Python implementation for the 'Number of Connected Components' problem.
Problem Statement
You have a graph of n nodes. You are given an integer n and an array edges where edges[i] = [ai, bi] indicates that there is an undirected edge between ai and bi in the graph.
Return the number of connected components in the graph.
Write a function countComponents(n: int, edges: List[List[int]]) -> int.
- •1 <= n <= 2000
- •0 <= len(edges) <= 5000
- •edges[i].length == 2
- •0 <= ai, bi < n
Examples
n = 5, edges = [[0,1],[1,2],[3,4]]
2
Nodes 0, 1, 2 form one component, and nodes 3, 4 form another component.
n = 5, edges = [[0,1],[1,2],[2,3],[3,4]]
1
All nodes are connected in a single path.
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
Ready to Solve?
Open the problem in PyRun's browser-based Python editor. Your code runs fully offline — no server required.
Recommended Python Resources
Expand your knowledge with related interactive tutorials, cheat sheets, and code comparisons.
Python Loops
Learn how to use Python loops to iterate over data. Master for loops, while loops, break, continue, and loop best practices with interactive examples.
How to Find the Length of a List in Python
Learn how to find the length of a list in Python using the len() function. Understand the O(1) time complexity and checking counts.
Python String Methods
A complete reference guide for Python string manipulation. Master formatting, searching, splitting, replacing, and checking string properties.
Python vs JavaScript: Which Programming Language is Best?
A comprehensive comparison between Python and JavaScript. Explore syntax differences, performance, use cases (backend vs frontend), and coding examples.