Document Insertion Methods for Singly Linked List in Python

Linked List/02_Insert_in_Singly_Linked_List.md

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+## Insertion in Singly Linked List
+
+Insertion in a Singly Linked List involves adding a new node with data to the list. There are several ways to insert a node depending on where we want to place it.
+
+### Types of Insertion
+
+1. **Insert at the Beginning**  
+   Inserting a node at the start of the list. This involves updating the new node’s `next` pointer to the current head and then updating the head to the new node.
+
+2. **Insert at the End**  
+   Adding a node at the end of the list. This requires traversing to the last node and updating its `next` pointer to the new node.
+
+3. **Insert at a Given Position**  
+   Inserting a node at a specific position in the list. This involves traversing to the position just before the desired location, updating pointers to link the new node into the list.
+
+### Node Structure
+
+The structure of the node remains the same as in a singly linked list, with each node containing a `val` and a pointer to the `next` node.
+
+```python
+class SinglyListNode:
+    def __init__(self, value):
+        self.val = value
+        self.next = None
+```
+
+### Example of Insertion Functions in Python
+
+Here's how you might implement each type of insertion:
+
+1. **Insert at the Beginning**
+
+```python
+def insert_at_beginning(head, value):
+    new_node = SinglyListNode(value)
+    new_node.next = head
+    return new_node
+```
+
+2. **Insert at the End**
+
+```python
+def insert_at_end(head, value):
+    new_node = SinglyListNode(value)
+    if not head:
+        return new_node
+    temp = head
+    while temp.next:
+        temp = temp.next
+    temp.next = new_node
+    return head
+```
+
+3. **Insert at a Given Position**
+
+```python
+def insert_at_position(head, value, position):
+    new_node = SinglyListNode(value)
+    if position == 1:
+        new_node.next = head
+        return new_node
+    temp = head
+    for _ in range(position - 2):
+        if temp is None:
+            return head  # Position is out of bounds
+        temp = temp.next
+    new_node.next = temp.next
+    temp.next = new_node
+    return head
+```
+
+### Complexity
+
+The time complexity for each insertion type is as follows:
+
+1. **Insert at the Beginning: 𝑂(1)**
+2. **Insert at the End: 𝑂(N) (due to traversal)**
+3. **Insert at a Given Position: 𝑂(N)**