Graph Valid Tree
Explore how to verify whether a graph with given nodes and edges forms a valid tree by ensuring it is connected and contains no cycles. Learn to implement these checks and enhance problem-solving skills relevant for coding interviews.
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Statement
Given n as the number of nodes and an array of the edges of a graph, find out if the graph is a valid tree. The nodes of the graph are labeled from to , and represents an undirected edge connecting the nodes and of the graph.
A graph is a valid tree when all the nodes are connected and there is no cycle between them.
Constraints:
-
n -
edges.length edges[i].length- ,
n - There are no repeated edges.
Examples
Understand the problem
Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:
Graph Valid Tree
Consider the following graph with four nodes:
What is the correct array of connected edges that would make the graph above?
edges = [[0, 1], [0, 2], [0, 3]]
edges = [[0, 1], [0, 2], [1, 2]]
edges = [[0, 1], [0, 2], [2, 3]]
Figure it out!
We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.
Try it yourself
Implement your solution in the following coding playground.
#include <iostream>#include <vector>#include <unordered_set>#include <stack>bool ValidTree(int n, std::vector<std::vector<int>>& edges) {// Replace this placeholder return statement with your codereturn false;}