[Coderust] Implementation of Linked List

 

 

Problem

 

 

 

---

 

Solution

 

 

class Node:
    def __init__(self, val):
        self.val = val
        self.next = None
        
        

class MyLinkedList:

    def __init__(self):
        self.head = None
        self.size = 0

    def get(self, index: int) -> int:
        if self.head==None or index < 0 or self.size <= index:
            return -1
        curr = self.head
        for _ in range(index):
            curr = curr.next
        return curr.val
        
        

    def addAtHead(self, val: int) -> None:
        node = Node(val)
        node.next = self.head
        self.head = node
        
        self.size += 1
        

    def addAtTail(self, val: int) -> None:
        curr = self.head
        if not curr:
            self.head = Node(val)
        else:
            while curr.next:
                curr = curr.next
            curr.next = Node(val)
        self.size += 1
        

    def addAtIndex(self, index: int, val: int) -> None:
        if index > self.size or index < 0:
            return
        
        if index == 0:
            self.addAtHead(val)
        else:
            curr = self.head
            for _ in range(index-1):
                curr = curr.next
            node = Node(val)
            node.next = curr.next
            curr.next = node
            
            self.size += 1
            
        

    def deleteAtIndex(self, index: int) -> None:
        if index >= self.size or index < 0:
            return
        
        curr = self.head
        if index == 0:
            self.head = curr.next
        else:
            for _ in range(index-1):
                curr = curr.next
            curr.next = curr.next.next
        
        self.size -= 1
        
        

        


# Your MyLinkedList object will be instantiated and called as such:
# obj = MyLinkedList()
# param_1 = obj.get(index)
# obj.addAtHead(val)
# obj.addAtTail(val)
# obj.addAtIndex(index,val)
# obj.deleteAtIndex(index)

 

Time Complexity

-

 

 

Space Complexity

-