reverse_linkedlist

public static SinglyLinkedListNode reverse(SinglyLinkedListNode llist) {
// Write your code here
    SinglyLinkedListNode curr = llist;
    SinglyLinkedListNode next = llist.next;
    
    llist.next = null;   // 1->null
    
    while(next != null){
        SinglyLinkedListNode temp = next.next;  // 3->4->5
        next.next = curr;       // 2->1->null
        curr = next;            // 2->1->null;
        next = temp;
    }
    
    return curr;

}