JAVA PROGRAM • LEVEL 17 — DATA STRUCTURES & ALGORITHMS IN JAVA
Implement Disjoint Set Union in Java
Learn implement disjoint set union in java with a complete, compiler-ready Java 17 example.
PROBLEM UNDERSTANDING
Input and expected output
No input required
true false
COMPLETE JAVA 17 PROGRAM
Complete Java 17 implementation
class DSU{int[] parent,size;DSU(int n){parent=new int[n];size=new int[n];for(int i=0;i<n;i++){parent[i]=i;size[i]=1;}}int find(int x){return parent[x]==x?x:(parent[x]=find(parent[x]));}void union(int a,int b){a=find(a);b=find(b);if(a==b)return;if(size[a]<size[b]){int t=a;a=b;b=t;}parent[b]=a;size[a]+=size[b];}}class Main{public static void main(String[] args){DSU dsu=new DSU(5);dsu.union(0,1);dsu.union(1,2);System.out.println(dsu.find(0)==dsu.find(2));System.out.println(dsu.find(0)==dsu.find(4));}}CURRENT STEP
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SELECTED LINE
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EXPECTED OUTPUT FOR THE SAMPLE
true false
PROGRAM EXPLANATION
Algorithm and explanation
- Initialize the deterministic sample values used for implement disjoint set union in java.
- Create the required object and apply DSU and Path compression to its state or behavior.
- Print the final result and compare it with the documented sample output.
This Java 17 example demonstrates DSU and Path compression through a complete, executable program. The values are intentionally small so students can trace each statement, verify the output, and then modify the example safely in the online compiler.
EFFICIENCY
Time and space complexity
O(α(n)) amortized
O(n)
DEBUGGING CHECKLIST
Common mistakes
Keep the class name Main and the entry method signature public static void main(String[] args) when using the online compiler.
Create an object before accessing instance members; static members can be accessed through the class name.
Java is case-sensitive, and every statement that requires a semicolon must end with one.