package main

import "fmt"

type Node struct {
    data int 
    next* Node 
}
type SLList struct {
    head* Node 
    tail* Node 
    size int
}
func (list* SLList) Print() {
    if list.size == 0 {
        fmt.Println("SLList empty")
        return
    }
    node := list.head
    for node != nil {
        fmt.Print(node.data, " ")        
        node = node.next 
    }
    fmt.Print("(", list.size, ") ")
    if list.head != nil {
        fmt.Print("(", list.head.data, "..", list.tail.data, ")")
    }
    fmt.Println()
}
func (list* SLList) PushLeft(data int) {
    node := Node{data: data}
    node.next = list.head 
    list.head = &node
    if list.size == 0 {
        list.tail = &node 
    }
    list.size++
}
func (list* SLList) PopLeft() int {
    if list.size == 0 {
        return 0
    }
    data := list.head.data
    list.head = list.head.next
    list.size--
    if list.size == 0 {
        list.tail = nil
    }
    return data
}
func (list* SLList) PushRight(data int) {
    if list.size == 0 {
        list.PushLeft(data)
        return
    }
    node := Node{data: data}
    list.tail.next = &node 
    list.tail = &node
    list.size++
}
func (list* SLList) PopRight() int {
    if list.size == 0 {
        fmt.Println("LList empty")
        return 0
    }
    if list.size == 1 {
        return list.PopLeft()
    }
    node := list.head     
    for node.next.next != nil {
        node = node.next
    }
    data := node.next.data 
    node.next = nil 
    list.tail = node
    list.size--
    return data
}
func (list* SLList) Reverse() {
    curr := list.head
    var prev* Node 
    var next* Node
    for curr != nil {
        next = curr.next 
        curr.next = prev 
        prev = curr 
        curr = next
    }
    list.head = prev
}
func main() {
    list := new(SLList)
    for i := 5; i > 0; i-- {
        list.PushRight(i * 100)
        list.Print()
    }
    list.Reverse()
    list.Print()
    for i := 0; i < 7; i++ {
        fmt.Println(list.PopRight())
        list.Print()
    }
}