week 13 completed.

.classpath

@@ -1,10 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<classpath>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER">
-		<attributes>
-			<attribute name="module" value="true"/>
-		</attributes>
-	</classpathentry>
-	<classpathentry kind="src" path=""/>
-	<classpathentry kind="output" path=""/>
-</classpath>

.gitignore

@@ -1,15 +1,4 @@
-/Week2.class
-/Week4.class
-/Week4Bonus.class
-/Task.class
-/Week9$1.class
-/Week9$2.class
-/Week9$3.class
-/Week9.class
-/Week9Gui.class
-/Task$CompareByTitle.class
-/Week9$4.class
-/Task$SortByTitleComparator.class
 .vscode
 .classpath
-.project
+.project
+*.class

.project

@@ -1,28 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<projectDescription>
-	<name>club-challenges</name>
-	<comment></comment>
-	<projects>
-	</projects>
-	<buildSpec>
-		<buildCommand>
-			<name>org.eclipse.jdt.core.javabuilder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
-	</buildSpec>
-	<natures>
-		<nature>org.eclipse.jdt.core.javanature</nature>
-	</natures>
-	<filteredResources>
-		<filter>
-			<id>1698871122678</id>
-			<name></name>
-			<type>30</type>
-			<matcher>
-				<id>org.eclipse.core.resources.regexFilterMatcher</id>
-				<arguments>node_modules|\.git|__CREATED_BY_JAVA_LANGUAGE_SERVER__</arguments>
-			</matcher>
-		</filter>
-	</filteredResources>
-</projectDescription>

spring24/week13/ParsePhone.java

@@ -0,0 +1,117 @@
+import java.io.File;
+import java.util.Scanner;
+
+/**
+ * This challenge is inspired from LeetCode Problem 193.
+ *
+ * Given an input file called "inut.txt" that contains a list of potential
+ * phone numbers on each line, determine if each line is a valid phone number.
+ *
+ * A valid phone number is defined as any sequence of digits that has the
+ * following characteristics:
+ * 1. It may contain a '+' at the start of the string, for the international
+ *   dialing code. The '+' is optional.
+ *
+ * 2. It may contain a '-' in the string, to separate the country code, area
+ *   code, and local number. The '-' is optional.
+ *
+ * 3. It may contain a '(' and ')' in the string, to enclose the area code.
+ */
+public class ParsePhone {
+    private static boolean isValidNumber(String number) {
+        char[] chars = number.toCharArray();
+
+        Queue q = new Queue();
+        for(int i = 0; i < chars.length; i++) {
+            if(Character.isDigit(chars[i])) 
+                q.enqueue(Integer.parseInt(chars[i] + ""));
+        }
+
+        if(q.getSize() != 10) return false;
+        else return true;
+    }
+
+    private static class Queue {
+        private Node head;
+        private Node tail;
+        private int size;
+
+        public Queue() {
+            head = null;
+            tail = head;
+            size = 0;
+        }
+
+        public void enqueue(int value) {
+            Node newNode = new Node(value);
+            if(head == null) {
+                head = newNode;
+                tail = head;
+                size++;
+                return;
+            }
+
+            tail.setNext(newNode);
+            tail = newNode;
+            size++;
+        }
+
+        public Node dequeue() {
+            if(head == null) return null;
+
+            Node tmp = head;
+            head = head.next;
+
+            size--;
+            return tmp;
+        }
+
+        public int getSize() {
+            return size;
+        }
+
+        private class Node {
+            private Node next;
+            private int value;
+
+            public Node(int value) {
+                this.value = value;
+            }
+
+            public boolean hasNext() {
+                return next != null;
+            }
+
+            public Node getNext() {
+                return next;
+            }
+
+            public void setNext(Node next) {
+                this.next = next;
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        File input = new File("input.txt");
+
+        if(input.exists() == false) {
+            System.out.println("File not found");
+            return;
+        }
+
+        try {
+            Scanner sc = new Scanner(input);
+
+            while(sc.hasNextLine()) {
+                String number = sc.nextLine();
+                System.out.println(isValidNumber(number) ? number : "Invalid");
+            }
+
+            sc.close();
+
+        } catch(Exception e) {
+            e.printStackTrace();
+        }
+    }
+}

spring24/week13/input.txt

@@ -0,0 +1,3 @@
+987-123-4567
+123 456 7890
+(123) 456-7890

spring24/week13/run.sh

@@ -0,0 +1,3 @@
+javac *.java
+java ParsePhone
+rm *.class

spring24/week9/input.sdku

@@ -0,0 +1,9 @@
+53..7....
+6..195...
+.98....6.
+8...6...3
+4..8.3..1
+7...2...6
+.6....28.
+...419..5
+....8..79