remove loop from linked list

//java 

Node remove(Node head){
//detect the loop
Node slow=head;
Node fast=head;
while(slow!=null&&fast!=null&&fast.next!=null){
slow=slow.next;
fast=fast.next.next;
if(slow==fast){
if(slow==head){
while(slow.next!=head){
slow=slow.next;
}
slow.next=null;
}
if(slow==fast){
slow=head;
while(slow.next!=fast.next){
if(slow==fast.next){
fast.next=null;
}
slow=slow.next;
fast=fast.next;
}
fast.next=null;
}
}
}

# Python program to detect and remove loop 
  
# Node class  
class Node: 
  
    # Constructor to initialize the node object 
    def __init__(self, data): 
        self.data = data 
        self.next = None
  
class LinkedList: 
  
    # Function to initialize head 
    def __init__(self): 
        self.head = None
  
    # Function to insert a new node at the beginning 
    def push(self, new_data): 
        new_node = Node(new_data) 
        new_node.next = self.head 
        self.head = new_node 
  
     
    def detectAndRemoveLoop(self): 
  
        if self.head is None : 
            return
        if self.head.next is None : 
            return
  
        slow = self.head  
        fast = self.head 
  
        # Move slow and fast 1 and 2 steps respectively 
        slow = slow.next
        fast = fast.next.next
  
        # Search for loop using slow and fast pointers 
        while (fast is not None): 
            if fast.next is None: 
                break 
            if slow == fast : 
                break
            slow = slow.next
            fast = fast.next.next
  
        # if loop exists 
        if slow == fast : 
            slow = self.head 
            while (slow.next != fast.next): 
                slow = slow.next
                fast = fast.next
              
            # Sinc fast.next is the looping point 
            fast.next = None # Remove loop 
  
  
    # Utility function to print the linked LinkedList 
    def printList(self): 
        temp = self.head 
        while(temp): 
            print temp.data, 
            temp = temp.next
  
  
# Driver program 
llist = LinkedList() 
llist.head = Node(50) 
llist.head.next = Node(20) 
llist.head.next.next = Node(15) 
llist.head.next.next.next = Node(4) 
llist.head.next.next.next.next = Node(10) 
  
# Create a loop for testing 
llist.head.next.next.next.next.next = llist.head.next.next
  
llist.detectAndRemoveLoop() 
  
print "Linked List after removing loop"
llist.printList() 
  
# This code is contributed by Nikhil Kumar Singh(nickzuck_007)