feat: added Nth Node From Linkedlist End Program -> Java

Beginner Level 📁/Nth_Node_From_End_LinkedList/Question.md

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+# Problem Statement
+
+Given a singly linked list, write a function to find the nth node from the end of the list. The function should return the data of the nth node. If `n` is greater than the length of the list, return `-1`.
+
+## Input
+
+- The linked list is constructed from `Node` instances, each containing:
+  - `data` (integer): The value of the node.
+  - `next` (Node): The next node in the list or `null` if it’s the last node.
+- `n` (integer): The position from the end of the list to find.
+
+## Output
+
+- An integer representing the data of the nth node from the end.
+- Return `-1` if `n` is larger than the length of the list.
+
+## Constraints
+
+1. `1 <= n <= 10^5`
+2. The linked list will contain only non-negative integers.
+3. The linked list length will be between `1` and `10^5`.
+
+## Example
+
+### Example 1
+
+**Input:**
+
+- Linked List: `0 -> 1 -> 2 -> 3 -> 4 -> 5 -> Null`
+- `n = 2`
+
+**Output:** `4`
+
+**Explanation:** The second node from the end of the list has the value `4`.
+
+### Example 2
+
+**Input:**
+
+- Linked List: `1 -> 2 -> 3 -> Null`
+- `n = 4`
+
+**Output:** `-1`
+
+**Explanation:** `n` is greater than the list length, so the function returns `-1`.
+
+### Time Complexity
+
+- **O(L)** where `L` is the length of the linked list. The function traverses the list twice, once to calculate the length and again to locate the nth node from the end.
+
+### Space Complexity
+
+- **O(1)**, as no extra space is used apart from a few pointers for traversal.

Beginner Level 📁/Nth_Node_From_End_LinkedList/Solution.java

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+public class Solution {
+    Node head;
+
+    static class Node {
+        int data;
+        Node next;
+
+        Node(int d) {
+            this.data = d;
+            this.next = null;
+        }
+    }
+
+    int nthNodeFromEnd(Node head, int n) {
+        Node temp = head;
+        int len = 0;
+        while (temp != null) {
+            len++;
+            temp = temp.next;
+        }
+        temp = head;
+        if (len < n)
+            return -1;
+        for (int i = 1; i < len - n + 1; i++) {
+            temp = temp.next;
+        }
+        return temp.data;
+
+    }
+
+    void printList() {
+        Node temp = head;
+        while (temp != null) {
+            System.out.print(temp.data + " -> ");
+            temp = temp.next;
+        }
+        System.out.print("Null");
+    }
+
+    public static void main(String[] args) {
+        Solution nnfl = new Solution();
+        nnfl.head = new Node(0);
+
+        Node a = new Node(1);
+        Node b = new Node(2);
+        Node c = new Node(3);
+        Node d = new Node(4);
+        Node e = new Node(5);
+        nnfl.head.next = a;
+        a.next = b;
+        b.next = c;
+        c.next = d;
+        d.next = e;
+        System.out.println(nnfl.nthNodeFromEnd(a, 2));
+        nnfl.printList();
+    }
+}

Beginner Level 📁/data.json

@@ -58,13 +58,17 @@
     "name": "Nimra Asalm",
     "githubUsername":"NimraAslamKhan"
   },
-
+{
     "name": "Dhara Bindal",
     "githubUsername": "bindaldhara"
 
-  }
+  },
   {
     "name": "Avid Coder",
     "githubUsername": "AvidCoder101"
+  },
+  {
+    "name":"Harshit Pachori",
+    "githubUsername":"HarshitPachori"
   }
 ]