Java solution "Partition List"

Linked List/Java/10_Partition_List.java

@@ -0,0 +1,116 @@
+// Question  https://leetcode.com/problems/partition-list/
+
+/**
+ * Initialize num1 and num2 nodes of below two linked lists as 0. 
+ * ListNode of values smaller than x.
+ * ListNode of values greater than or equal to x.
+ * 
+ * Now iterate through the original linked list.
+ * If a node’s value is less than x then append it at the end of the num1 list.
+ * If the value is greater than or equal to x, then at the end of the num2 list.
+ * 
+ * Now concatenate both two lists.
+ */
+
+import java.util.Scanner;
+
+class LinkedList {
+    ListNode head; // head of list
+
+    /* Linked list Node*/
+    static class ListNode {
+        int val;
+        ListNode next;
+        ListNode(int val)
+        {
+            this.val = val;
+            next = null;
+        }
+    }
+
+    public static ListNode partition(ListNode head, int x) {
+        ListNode res1 = new ListNode(0), num1 = res1, res2 = new ListNode(0), num2 = res2;
+        while(head != null)
+        {
+            if(head.val < x){
+                num1.next = head;
+                num1 = head;
+            }else{
+                num2.next = head;
+                num2 = head;
+            }
+            head = head.next;
+        }
+        num2.next = null;
+        num1.next = res2.next;
+        return res1.next;
+    }
+
+    public void push(int new_data)
+    {
+        ListNode new_node = new ListNode(new_data);
+        ListNode temp = head;
+
+        while(temp.next != null)
+        {
+            temp = temp.next;
+        }
+
+        temp.next = new_node;
+    }
+
+    public void printList()
+    {
+        ListNode tnode = head;
+        while (tnode != null) {
+            System.out.print(tnode.val + " ");
+            tnode = tnode.next;
+        }
+    }
+
+    public static void main(String[] args)
+    {
+        Scanner sc =new Scanner(System.in);
+
+        LinkedList llist = new LinkedList();
+
+        System.out.println("\nEnter Linked list size:");
+        int n = sc.nextInt();
+
+        if(llist.head == null)
+        {
+            int e = sc.nextInt();
+            llist.head = new ListNode(e);
+        }
+
+        for(int i = 1;i < n;i ++)
+        {
+            int e = sc.nextInt();
+            llist.push(e);
+        }
+
+        System.out.println("\nCreated Linked list is:");
+        llist.printList();
+
+        System.out.println("\nEnter the partition number:");
+       int x = sc.nextInt();
+
+        ListNode res = partition(llist.head, x);
+
+        while(res!=null){
+            System.out.println(res.val);
+            res=res.next;
+        }
+    }
+}
+
+// Examples
+/**
+ * Example 1:
+ * Input: head = [1,4,3,2,5,2], x = 3
+ * Output: [1,2,2,4,3,5]
+ *
+ * Example 2:
+ * Input: head = [2,1], x = 2
+ * Output: [1,2]
+ */