Skip Lists in Go

package main

import (
	"fmt"	
	"math/rand"
	"time"
)

const maxLevel = 4

type skipListNode struct {
	value int
	next  []*skipListNode
}

type skipList struct {
	head  *skipListNode
	level int
}

func newSkipList() *skipList {
	head := &skipListNode{
		value: -1,
		next:  make([]*skipListNode, maxLevel),
	}
	return &skipList{head, 1}
}

func (sl *skipList) randomLevel() int {
	level := 1
	for ; rand.Float32() < 0.5 && level < maxLevel; level++ {
	}
	return level
}

func (sl *skipList) Insert(value int) {
	update := make([]*skipListNode, maxLevel)
	curr := sl.head
	for i := sl.level - 1; i >= 0; i-- {
		for curr.next[i] != nil && curr.next[i].value < value {
			curr = curr.next[i]
		}
		update[i] = curr
	}
	
	newLevel := sl.randomLevel()
	if newLevel > sl.level {
		for i := sl.level; i < newLevel; i++ {
			update[i] = sl.head
		}
		sl.level = newLevel
	}
	
	newNode := &skipListNode{
		value: value,
		next:  make([]*skipListNode, newLevel),
	}
	
	for i := 0; i < newLevel; i++ {
		newNode.next[i] = update[i].next[i]
		update[i].next[i] = newNode
	}
}

func (sl *skipList) Search(value int) bool {
	curr := sl.head
	for i := sl.level - 1; i >= 0; i-- {
		for curr.next[i] != nil && curr.next[i].value < value {
			curr = curr.next[i]
		}
	}
	curr = curr.next[0]
	return curr != nil && curr.value == value
}

func main() {
	rand.Seed(time.Now().UnixNano())
	sl := newSkipList()
	sl.Insert(42)
	sl.Insert(73)
	sl.Insert(91)
	
	fmt.Println("Search 73:", sl.Search(73)) // Output: Search 73: true
	fmt.Println("Search 50:", sl.Search(50)) // Output: Search 50: false
}