Hash Table using Linear Probing 🎉

Author: deadcoder0904

examples/datastructures/hash-table-linear-probing.js

@@ -0,0 +1,39 @@
+class HashTable {
+	constructor() {
+		this.table = new Array(137);
+		this.values = new Array(137);
+	}
+
+	betterHash(word) {
+		let total = 0;
+		for(let i = 0; i < word.length; i++)
+			total = 37 * total + word.toLowerCase().charCodeAt(i);
+		return total % this.table.length;
+	}
+
+	put(key, value) {
+		const pos = this.betterHash(key);
+		while(this.table[pos] != undefined)
+			pos++;
+		this.table[pos] = key;
+		this.values[pos] = value;
+	}
+
+	get(key) {
+		const hash = this.betterHash(key);
+		for(let i = hash;this.table[hash] != undefined; i++)
+			if(this.table[hash] == key)
+				break;
+		return this.table[hash];
+	}
+
+	showAll() {
+		let str = "";
+		for (let i = 0; i < this.table.length; i++)
+			if(this.table[i] !=undefined)
+				str += this.values[i] + " : " + this.table[i] + "\n";
+		return str;
+	}
+}
+
+module.exports = HashTable;

examples/datastructures/hash-table-separate-chaining.js

@@ -34,8 +34,8 @@ class HashTable {
 
 	showAll() {
 		let str = "";
-		for (let i = 0; i < this.table.length && this.table[i] !=undefined; i++)
-			for (let j = 0; j < this.table[i].length && this.table[i][j] !=undefined; j++)
+		for (let i = 0; i < this.table.length; i++)
+			for (let j = 0; j < this.table[i].length; j++)
 				str += i + " : " + this.table[i] + "\n";
 		return str;
 	}

test/datastructures/hash-table-linear-probing.test.js

@@ -0,0 +1,30 @@
+const expect = require('chai').expect;
+const HashTable = require('../../examples/datastructures/hash-table-linear-probing');
+
+describe('=> HASH TABLE USING LINEAR PROBING', function() {
+	let people;
+	before(function () {
+		people = new HashTable();
+	});
+
+	it('should create an Empty Hash Table', function(done) {
+		expect(people.table.length).to.deep.equal(137);
+		done();
+	});
+
+	it('should put value into the Hash Table',function() {
+		people.put("Diana",13);
+		people.put("Clayton",14);
+		people.put("Raymond",47);
+		people.put("Nadia",28);
+		people.put("Afzar",51);
+		expect(people.showAll()).to.equal("13 : Diana\n51 : Afzar\n14 : Clayton\n47 : Raymond\n28 : Nadia\n");
+	});
+
+	it('should get value from the Hash Table',function() {
+		expect(people.get("Nadia")).to.equal("Nadia");
+		expect(people.get("Diana")).to.equal("Diana");
+		expect(people.get("Azhar")).to.equal(undefined);
+	});
+
+});