This is a Java Program to implement Sparse Vector. Sparse vectors are useful implementation of vectors that mostly contains zeroes. Here sparse vectors consists of (index, value) pairs.
Here is the source code of the Java Program to implement Sparse Vector. The Java program is successfully compiled and run on a Windows system. The program output is also shown below.
/** ** Java Program to implement Sparse Vector **/ import java.util.Scanner; import java.util.TreeMap; import java.util.Map; /** Class SparseVector **/ class SparseVector { /* Tree map is used to maintain sorted order */ private TreeMap<Integer, Double> st; private int N; /** Constructor **/ public SparseVector(int N) { this.N = N; st = new TreeMap<Integer, Double>(); } /** Function to insert a (key, value) pair **/ public void put(int i, double value) { if (i < 0 || i >= N) throw new RuntimeException("\nError : Out of Bounds\n"); if (value == 0.0) st.remove(i); else st.put(i, value); } /** Function to get value for a key **/ public double get(int i) { if (i < 0 || i >= N) { throw new RuntimeException("\nError : Out of Bounds\n"); } if (st.containsKey(i)) return st.get(i); else return 0.0; } /** Function to get size of the vector **/ public int size() { return N; } /** Function to get dot product of two vectors **/ public double dot(SparseVector b) { SparseVector a = this; if (a.N != b.N) throw new RuntimeException("Error : Vector lengths are not same"); double sum = 0.0; if (a.st.size() <= b.st.size()) { for (Map.Entry<Integer, Double> entry : a.st.entrySet()) if (b.st.containsKey(entry.getKey())) sum += a.get(entry.getKey()) * b.get(entry.getKey()); } else { for (Map.Entry<Integer, Double> entry : b.st.entrySet()) if (a.st.containsKey(entry.getKey())) sum += a.get(entry.getKey()) * b.get(entry.getKey()); } return sum; } /** Function to get sum of two vectors **/ public SparseVector plus(SparseVector b) { SparseVector a = this; if (a.N != b.N) throw new RuntimeException("Error : Vector lengths are not same"); SparseVector c = new SparseVector(N); for (Map.Entry<Integer, Double> entry : a.st.entrySet()) c.put(entry.getKey(), a.get(entry.getKey())); for (Map.Entry<Integer, Double> entry : b.st.entrySet()) c.put(entry.getKey(), b.get(entry.getKey()) + c.get(entry.getKey())); return c; } /** Function toString() for printing vector **/ public String toString() { String s = ""; for (Map.Entry<Integer, Double> entry : st.entrySet()) s += "(" + entry.getKey() + ", " + st.get(entry.getKey()) + ") "; return s; } } /** Class SparseVector **/ public class SparseVectorTest { public static void main(String[] args) { System.out.println("Sparse Vector Test\n"); Scanner scan = new Scanner(System.in); System.out.println("Enter size of sparse vectors"); int n = scan.nextInt(); SparseVector v1 = new SparseVector(n); SparseVector v2 = new SparseVector(n); System.out.println("\nEnter number of entries for vector 1"); int n1 = scan.nextInt(); System.out.println("Enter "+ n1 +" (int, double) pairs"); for (int i = 0; i < n1; i++) v1.put(scan.nextInt(), scan.nextDouble() ); System.out.println("\nEnter number of entries for vector 2"); int n2 = scan.nextInt(); System.out.println("Enter "+ n2 +" (int, double) pairs"); for (int i = 0; i < n2; i++) v2.put(scan.nextInt(), scan.nextDouble() ); System.out.println("\n"); System.out.println("Vector v1 = " + v1); System.out.println("Vector v2 = " + v2); System.out.println("\nv1 dot v2 = " + v1.dot(v2)); System.out.println("v1 + v2 = " + v1.plus(v2)); } }
Sparse Vector Test Enter size of sparse vectors 70000 Enter number of entries for vector 1 4 Enter 4 (int, double) pairs 3 1.0 2500 6.3 5000 10.0 60000 5.7 Enter number of entries for vector 2 3 Enter 3 (int, double) pairs 1 7.5 3 5.7 2500 -6.3 Vector v1 = (3, 1.0) (2500, 6.3) (5000, 10.0) (60000, 5.7) Vector v2 = (1, 7.5) (3, 5.7) (2500, -6.3) v1 dot v2 = -33.989999999999995 v1 + v2 = (1, 7.5) (3, 6.7) (5000, 10.0) (60000, 5.7)
Related posts:
Lập trình mạng với java
The Registration API becomes RESTful
Iterable to Stream in Java
Java Program to Implement Quick Sort Using Randomization
A Custom Data Binder in Spring MVC
Explain about URL and HTTPS protocol
Java Program to Implement Sparse Matrix
Java Program to Implement CountMinSketch
Java Program to Use rand and srand Functions
Hướng dẫn Java Design Pattern – Visitor
Reading an HTTP Response Body as a String in Java
Java Program to Implement CopyOnWriteArraySet API
ThreadPoolTaskExecutor corePoolSize vs. maxPoolSize
Java Program to Implement Trie
Spring Webflux with Kotlin
Java Program to Find the Minimum value of Binary Search Tree
Encode/Decode to/from Base64
Java Program to Perform Inorder Non-Recursive Traversal of a Given Binary Tree
An Intro to Spring Cloud Contract
Fixing 401s with CORS Preflights and Spring Security
Hướng dẫn Java Design Pattern – Transfer Object
Extract network card address
Câu lệnh điều khiển vòng lặp trong Java (break, continue)
Java Program to Generate Random Hexadecimal Byte
Java Program to Implement Quick Sort with Given Complexity Constraint
Guide to CountDownLatch in Java
Compare Two JSON Objects with Jackson
Java Program to Perform Complex Number Multiplication
Tránh lỗi NullPointerException trong Java như thế nào?
Java Program to Implement Branch and Bound Method to Perform a Combinatorial Search
Java 8 Stream findFirst() vs. findAny()
Vector trong Java