Java - Queues

java/queue/README.md

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+# Queues
+
+## What are queues? 
+Queues are just like the line you have in a supermarket. You have a line that is First In and First Out. This is called FIFO structure. But what is the hype surrounding queues? 
+
+## What can you use queues for? 
+Queue data structures are commonly used in various scenarios where items or tasks need to be processed in a first-in, first-out order. Remember these are a few of the many ways that queues can be used!
+
+1. Job Scheduling: In computer systems and networks, queues are used to handle job scheduling. Jobs are added to a queue and processed in the order they were received. 
+2. Call Center Phone Systems: In call center phone systems, incoming calls are added to a queue, and customers are served in the order their calls were received. 
+3. Online Multiplayer Games: In online multiplayer games, queues are often used to manage the order in which players join game sessions or matchmaking queues. 
+
+## What can you do with Queue Data Structure? 
+- Dequeue: deletes and returns the element that is at the front of the queue
+- Enqueue: inserts the element at the back of the queue
+- Peek: peeks at the front of the queue and returns the first element
+- isEmpty: is the queue empty? It checks it
+- isFull: is the queue full? It checks it
+
+## Methods that can be used for Queues
+1. add() - adds an element to the queue
+2. remove() - removes an element into the queue
+3.  offer() - inserts an element into the queue and if successful will return true 
+4. peek() - returns the head of the queue; if empty will return null
+5. poll() - removes and returns the head of the queue; if empty will return null
+6. element() - returns the head of the queue; if empty will throw an exception
+7. peek() - returns the head of the queue; if empty will return null
+

java/queue/guess.java

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+package java.queue;
+
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.Scanner;
+import java.util.Random;
+
+// This is a small guessing game that uses linkedlists and queues
+
+public class guess {
+    public static void main(String[] args) {
+        guess();
+    }
+
+    public static void guess() {
+        Random random = new Random();
+        int secretNumber = random.nextInt(100) + 1;
+        Queue<Integer> previousGuesses = new LinkedList<>();
+
+        System.out.println("We are going to play a quick guessing gam \n");
+        System.out.println("Guess a number between 1 and 100 \n");
+
+        // Scanner allows you to add inputs and for the system to recognize it
+        Scanner scanner = new Scanner(System.in);
+
+        // uses a while loop to allow you to continue to guess the number until you get
+        // it
+        while (true) {
+            System.out.println("Guess the number");
+            String input = scanner.nextLine();
+
+            if (!input.matches("\\d+")) {
+                System.out.println("Please enter a valid number.");
+                continue;
+            }
+
+            int guess = Integer.parseInt(input);
+
+            if (guess < secretNumber) {
+                System.out.println("Too low! Try again");
+                // This adds the guess to the line
+                previousGuesses.add(guess);
+            } else if (guess > secretNumber) {
+                System.out.println("Too high! Try again");
+                previousGuesses.add(guess);
+            } else {
+                System.out.println("You got it! It was " + secretNumber);
+                break;
+            }
+            System.out.println("Previous guess" + previousGuesses);
+        }
+        scanner.close();
+    }
+}