codingstuff.io
ExploreTutorialsProblemsCS Subjects
Get Started
ExploreTutorialsProblemsCS Subjects
Get Started
codingstuff.io

Master the art of building software through interactive tutorials, real-world problems, and guided projects.

Pune, Maharashtra, India

codingstuffmail@gmail.com

Product

  • Explore
  • Tutorials
  • Problems
  • CS Subjects

Company

  • About
  • Contact
  • Privacy Policy
  • Terms & Conditions
  • Sitemap

© 2026 codingstuff.io. All rights reserved.

Built with ❤️ for developers everywhere

ProblemsRedundant Connection

Redundant Connection

Medium
GraphsUnion Find

In this problem, a tree is an undirected graph that is connected and has no cycles.

You are given a graph that started as a tree with n nodes labeled from 1 to n, with one additional edge added. The added edge has two different vertices chosen from 1 to n, and was not an edge that already existed. The graph is represented as an array edges of length n where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the graph.

Return an edge that can be removed so that the resulting graph is a tree of n nodes. If there are multiple answers, return the answer that occurs last in the input.

 

Example 1:

Input: edges = [[1,2],[1,3],[2,3]]
Output: [2,3]

Example 2:

Input: edges = [[1,2],[2,3],[3,4],[1,4],[1,5]]
Output: [1,4]

 

Constraints:

  • n == edges.length
  • 3 <= n <= 1000
  • edges[i].length == 2
  • 1 <= ai < bi <= edges.length
  • ai != bi
  • There are no repeated edges.
  • The given graph is connected.

Related Problems

View all
Number of Islands
Medium•Graphs
Max Area of Island
Medium•Graphs
Clone Graph
Medium•Graphs
Wall and Gates
Medium•Graphs
Rotting Oranges
Medium•Graphs
Pacific Atlantic Water Flow
Medium•Graphs
Input:
edges = [[1,2],[1,3],[2,3]]