package me.ramswaroop.linkedlists;
import me.ramswaroop.common.SingleLinkedList;
import me.ramswaroop.common.SingleLinkedNode;
/**
* Created by IntelliJ IDEA.
*
* @author: ramswaroop
* @date: 7/15/15
* @time: 12:12 AM
*/
public class MaximumSumLinkedList {
/**
* Constructs a linked list that contains maximum sum path from start to end
* from two linked lists starting at {@param node1} and {@param node2}.
* <p/>
* Example,
* Input:
* List1 = 1->3->30->90->120->240->511
* List2 = 0->3->12->32->90->125->240->249
* <p/>
* Output: Following is maximum sum linked list out of two input lists
* List = 1->3->12->32->90->125->240->511
* <p/>
* NOTE: We switch at 3 and 240 to get above maximum sum linked list
*
* @param node1
* @param node2
* @param <E>
* @return
*/
public static <E extends Comparable<E>> SingleLinkedNode<E> maximumSumLinkedList(SingleLinkedNode<E> node1,
SingleLinkedNode<E> node2) {
boolean isList1 = true;
SingleLinkedNode<E> head = node1, node = node1, curr1 = node1.next, curr2 = node2.next;
while (curr1 != null || curr2 != null) {
// if either of the list runs out first
if (curr1 == null) {
// check whether we are in list 1 currently
if (isList1) break;
node.next = curr2;
node = node.next;
curr2 = curr2.next;
continue;
}
if (curr2 == null) {
// check whether we are in list 2 currently
if (!isList1) break;
node.next = curr1;
node = node.next;
curr1 = curr1.next;
continue;
}
// switch lists once both node values match
if (curr1.item.compareTo(curr2.item) == 0) {
isList1 = !isList1;
}
if (isList1) {
node.next = curr1;
} else {
node.next = curr2;
}
node = node.next;
curr1 = curr1.next;
curr2 = curr2.next;
}
return head;
}
public static void main(String a[]) {
SingleLinkedList<Integer> linkedList1 = new SingleLinkedList<>();
linkedList1.add(00);
linkedList1.add(11);
linkedList1.add(22);
linkedList1.add(33);
linkedList1.add(44);
linkedList1.add(55);
linkedList1.add(88);
linkedList1.add(90);
linkedList1.printList();
SingleLinkedList<Integer> linkedList2 = new SingleLinkedList<>();
linkedList2.add(12);
linkedList2.add(21);
linkedList2.add(26);
linkedList2.add(33);
linkedList2.add(34);
linkedList2.add(67);
linkedList2.printList();
SingleLinkedList.printList(maximumSumLinkedList(linkedList1.head, linkedList2.head));
}
}