[Sync Iteration] go/simple-linked-list/1

solutions/go/simple-linked-list/1/simple_linked_list.go

@@ -0,0 +1,112 @@
+package linkedlist
+
+import "errors"
+
+// Define the List and Element types here.
+type List struct {
+	first *Element
+	last  *Element
+	len   int
+}
+type Element struct {
+	value int
+	next  *Element
+}
+
+func New(elements []int) *List {
+	if len(elements) == 0 {
+		return &List{}
+	}
+
+	n := &Element{value: elements[0]}
+	l := 1
+	curr := n
+
+	for _, v := range elements[1:] {
+		curr.next = &Element{value: v}
+		curr = curr.next
+		l++
+	}
+
+	return &List{n, curr, l}
+}
+
+func (l *List) Size() int {
+	return l.len
+}
+
+func (l *List) Push(element int) {
+	if l.Size() == 0 {
+		l.first = &Element{value: element}
+		l.last = l.first
+	} else {
+		l.last.next = &Element{value: element}
+		l.last = l.last.next
+	}
+
+	l.len++
+}
+
+func (l *List) Pop() (int, error) {
+	if l.Size() == 0 {
+		return 0, errors.New("Empty list")
+	}
+
+	if l.first.next == nil {
+		v := l.first.value
+		l.first, l.last = nil, nil
+		l.len--
+		return v, nil
+	}
+
+	var prev *Element
+	curr := l.first
+
+	for curr.next != nil {
+		prev, curr = curr, curr.next
+	}
+
+	prev.next = nil
+	l.last = prev
+	l.len--
+
+	return curr.value, nil
+}
+
+func (l *List) Array() []int {
+	a := make([]int, 0, l.Size())
+	if l.Size() == 0 {
+		return a
+	}
+
+	n := l.first
+	for n.next != nil {
+		a = append(a, n.value)
+		n = n.next
+	}
+	a = append(a, n.value)
+
+	return a
+}
+
+func (l *List) Reverse() *List {
+	if l.Size() <= 1 {
+		return l
+	}
+
+	var prev *Element
+	curr := l.first
+
+	l.last = l.first
+
+	for curr != nil {
+		next := curr.next
+		curr.next = prev
+		prev = curr
+		curr = next
+	}
+
+	l.first = prev
+
+	return l
+}