Fixes #2360 Palindrome Linked List

aitorfi · aitorfi · commit a3b7d0b5588b · 2021-10-27T19:08:02.000+02:00
diff --git a/Misc/PalindromeSinglyLinkedList.java b/Misc/PalindromeSinglyLinkedList.java
@@ -0,0 +1,59 @@
+package Misc;
+
+import java.util.Stack;
+
+/**
+ * A simple way of knowing if a singly linked list is palindrome is to
+ * push all the values into a Stack and then compare the list to popped
+ * vales from the Stack.
+ * 
+ * See more: https://www.geeksforgeeks.org/function-to-check-if-a-singly-linked-list-is-palindrome/
+ */
+public class PalindromeSinglyLinkedList {
+    public static void main(String[] args) {
+        Node node5 = new Node(3, null);
+        Node node4 = new Node(2, node5);
+        Node node3 = new Node(1, node4);
+        Node node2 = new Node(2, node3);
+        Node node1 = new Node(3, node2);
+        // Node node1 = new Node(2, node2);
+
+        if (isPalindrome(node1)) {
+            System.out.println("It's a palindrome list");
+        } else {
+            System.out.println("It's NOT a palindrome list");
+        }
+    }
+
+    public static boolean isPalindrome(Node head) {
+        boolean ret = true;
+        Node tempNode = head;
+        Stack<Integer> linkedListValues = new Stack<>();
+
+        while (tempNode != null) {
+            linkedListValues.push(tempNode.data);
+            tempNode = tempNode.nextNode;
+        }
+
+        while (head != null) {
+            if (head.data != linkedListValues.pop()) {
+                ret = false;
+                break;
+            }
+
+            head = head.nextNode;
+        }
+
+        return ret;
+    }
+}
+
+class Node {
+    int data;
+    Node nextNode;
+
+    public Node(int data, Node nextNode) {
+        this.data = data;
+        this.nextNode = nextNode;
+    }
+}
