/// <summary>
/// https://leetcode.com/explore/interview/card/top-interview-questions-easy/93/linked-list/771/
/// </summary>
public ListNode MergeTwoLists(ListNode l1, ListNode l2)
{
ListNode head = new ListNode()
{
data = 0
};
ListNode tail = head;
while (l1 != null && l2 != null)
{
if (l1.data < l2.data)
{
tail.next = l1;
l1 = l1.next;
}
else
{
tail.next = l2;
l2 = l2.next;
}
tail = tail.next;
}
if (l1 == null)
{
tail.next = l2;
}
if (l2 == null)
{
tail.next = l1;
}
return(head.next);
}
static ListNode ReversePartOfLinkedList(ListNode node, int m, int n)
{
ListNode prev = null;
ListNode current = node;
ListNode next = null;
return(node);
}
public ListNode sortedMerge(ListNode headA, ListNode headB)
{
/* a dummy first node to
* hang the result on */
ListNode dummyNode = new ListNode()
{
data = 0
};
/* tail points to the
* last result node */
ListNode tail = dummyNode;
while (true)
{
/* if either list runs out,
* use the other list */
if (headA == null)
{
tail.next = headB;
break;
}
if (headB == null)
{
tail.next = headA;
break;
}
/* Compare the data of the two
* lists whichever lists' data is
* smaller, append it into tail and
* advance the head to the next Node
*/
if (headA.data <= headB.data)
{
tail.next = headA;
headA = headA.next;
}
else
{
tail.next = headB;
headB = headB.next;
}
/* Advance the tail */
tail = tail.next;
}
return(dummyNode.next);
}
/// Modify the linked list so that all even elements appear before odd elements
/// Order of appearance of elements must not change
static ListNode EvenAndOddList(ListNode node)
{
ListNode evenStart = null;
ListNode evenEnd = null;
ListNode oddStart = null;
ListNode oddEnd = null;
while (node != null)
{
if (node.data % 2 == 0)
{
if (evenStart == null)
{
evenStart = node;
evenEnd = evenStart;
}
else
{
evenEnd.next = node;
evenEnd = evenEnd.next;
}
}
else
{
if (oddStart == null)
{
oddStart = node;
oddEnd = oddStart;
}
else
{
oddEnd.next = node;
oddEnd = oddEnd.next;
}
}
node = node.next;
}
evenEnd.next = oddStart;
node = evenStart;
return(node);
}
public void Main()
{
ListNode node = LinkedList.CreateLinkedList();
//node = ReverseLinkedList(node);
//node = EvenAndOddList(node);
ListNode llist = new ListNode()
{
data = 2,
next = new ListNode()
{
data = 9,
next = new ListNode()
{
data = 3
}
}
};
ListNode llist2 = new ListNode()
{
data = 5,
next = new ListNode()
{
data = 9,
next = new ListNode()
{
data = 4
}
}
};
//var res = MergeTwoLists(llist, llist2);
//var res = sortedMerge(llist, llist2);
var res = AddTwoNumbers(llist, llist2);
Console.ReadLine();
Console.WriteLine();
}
static ListNode ReverseLinkedList(ListNode node)
{
ListNode prev = null;
ListNode current = node;
ListNode next = null;
while (current != null)
{
// save next node before changing
next = current.next;
// do the reversal
current.next = prev;
// set pointers for next iteration
prev = current;
current = next;
}
node = prev;
return(node);
}
/// <summary>
/// https://leetcode.com/explore/interview/card/top-interview-questions-medium/107/linked-list/783/#
/// </summary>
public ListNode AddTwoNumbers(ListNode l1, ListNode l2)
{
ListNode res = new ListNode();
ListNode head = res;
int carry = 0;
while (l1 != null && l2 != null)
{
int sum = l1.data + l2.data + carry;
if (sum / 10 == 1)
{
carry = 1;
sum = sum % 10;
}
else
{
carry = 0;
}
ListNode node = new ListNode()
{
data = sum
};
res.next = node;
res = res.next;
l1 = l1.next;
l2 = l2.next;
}
while (l1 != null)
{
int sum = l1.data + carry;
if (sum / 10 == 1)
{
carry = 1;
sum = sum % 10;
}
else
{
carry = 0;
}
ListNode node = new ListNode()
{
data = sum
};
res.next = node;
res = res.next;
l1 = l1.next;
}
while (l2 != null)
{
int sum = l2.data + carry;
if (sum / 10 == 1)
{
carry = 1;
sum = sum % 10;
}
else
{
carry = 0;
}
ListNode node = new ListNode()
{
data = sum
};
res.next = node;
res = res.next;
l2 = l2.next;
}
if (carry == 1)
{
ListNode node = new ListNode()
{
data = carry
};
res.next = node;
}
return(head.next);
}
