//recursive function to find the kth from last element
func findKFromLastRecr(head *list.Element, k int, wrapper *WrapObj) *list.Element {
if head == nil {
return nil
}
resNode := findKFromLastRecr(head.Next(), k, wrapper)
//Increment the count on every return call
wrapper.count = (wrapper.count) + 1
if wrapper.count == k {
return head
}
return resNode
}
//Iterative function to find the kth from last element
func findKFromLast(l *list.List, k int) *list.Element {
size := l.Len()
//Base condition. If the size of the list is less than k then kth element cannot be found
if size < k {
return nil
}
var elem *list.Element
elem = l.Front()
for i := 1; i < k; i++ {
elem = elem.Next()
}
var first *list.Element
for first = l.Front(); first != nil && elem != nil; elem, first = elem.Next(), first.Next() {
//return the current node when current+k position is nil
if elem.Next() == nil {
return first
}
}
return nil
}
func findLoopsInList(l *list.List) *list.Element {
if l == nil {
return nil
}
var head *list.Element
var slow *list.Element
var fast *list.Element
head = l.Front()
for slow, fast = l.Front(), l.Front(); slow != nil && fast != nil; slow, fast = slow.Next(), fast.Next().Next() {
if slow == fast {
break
}
}
if fast == nil || fast.Next() == nil {
return nil
}
slow = head
for slow != fast {
slow = slow.Next()
fast = fast.Next()
}
return fast
}
//Function to add the list
func addLists(l *list.List, m *list.List) *list.List {
if l == nil && m == nil {
return nil
}
lLength := l.Len()
mLength := m.Len()
carry := 0
value := 0
resList := list.New()
var e *list.Element
var f *list.Element
for e, f = l.Front(), m.Front(); e != nil && f != nil; e, f = e.Next(), f.Next() {
value = carry + e.Value.(int) + f.Value.(int)
//get the carry and value
carry = 0
carry = value / 10
value = value % 10
resList.PushFront(value)
}
//To identify the long list if the size is different
var p *list.Element
if lLength > mLength {
p = e
} else {
p = f
}
for ; p != nil; p = p.Next() {
value = carry + p.Value.(int)
carry = 0
carry = value / 10
value = value % 10
resList.PushFront(value)
}
if carry != 0 {
resList.PushFront(carry)
}
return resList
}
