bubble sort implementation on linked lists

Question

I have to implement a BubbleSort algorithm on a Linked List instead of an array. I\'m new to java so I don\'t really know how to put it in code. But I gave it a try and here

Answer 1

Example linked list bubble sort that doesn't emulate random access using an elementAt() function, and instead operates via the links between nodes, so time complexity is O(n^2) instead of being much worse. "end" is used to keep track of where the sorted nodes at the end of the list begin. I used the example code from the question and didn't bother changing the class to comparable, using toString() instead for the compare. I used a dummy node to simplify the code.

void bubbleSort()
{ 
    if(first == null)
        return;
    SinglyNode dmy = new SinglyNode("dummy");  // dummy node
    dmy.next = first;
    // end == null or first sorted node at end of list
    SinglyNode end = null;
    int swap;
    do{
        swap = 0;
        SinglyNode prv = dmy;           // previous node
        while(true){
            SinglyNode cur = prv.next;  // current node
            SinglyNode nxt = cur.next;  // next node
            if(nxt == end){             // if at end node
                end = cur;              //  update end = cur
                break;                  //  and break
            }
            // if out of order, swap nodes
            if(cur.names.toString().compareTo(nxt.names.toString()) > 0){
                cur.next = nxt.next;
                nxt.next = cur;
                prv.next = nxt;
                swap = 1;
            }
            prv = prv.next;             // advance to next node
        }
    }while(swap != 0);                  // repeat untl no swaps
    first = dmy.next;                   // update first
}