01-remove-duplicates.go

package main

import (
	"fmt"
	"os"
)

type Node struct {
	value string
	next  *Node
}

func (n *Node) ToString() string {
	nextVal := "nil"
	if n.next != nil {
		nextVal = n.next.value
	}
	return fmt.Sprintf("{value: %s, next: %s}", n.value, nextVal)
}

type LinkedList struct {
	head *Node
	tail *Node
}

func (l *LinkedList) add(value string) Node {
	var newNode Node = Node{value, nil}
	if l.head == nil {
		l.head = &newNode
	}
	if l.tail != nil {
		l.tail.next = &newNode
	}
	l.tail = &newNode

	return newNode
}

func (l *LinkedList) getNode(search string) *Node {
	current := l.head
	for search != current.value {
		fmt.Printf("searchin if element %s is equal to %s\n", current.ToString(), search)
		if current.next == nil {
			fmt.Println("[error] element not found in linked list")
			os.Exit(1)
		}
		current = current.next
	}
	fmt.Printf("found element with value %s : %s\n", search, current.ToString())
	return current
}

func (l *LinkedList) remove(search string) {
	current := l.getNode(search)
	l.removeNode(current)
}

func (l *LinkedList) removeNode(node *Node) {
	temp := l.head
	if node == nil {
		fmt.Printf("Error, node is empty")
		return
	}
	if l.head == node {
		l.head = temp.next
		return
	}
	for temp.next != node {
		temp = temp.next
	}
	if l.tail == node {
		l.tail = temp
		l.tail.next = nil
		return
	}
	if temp.next == node {
		temp.next = node.next
	}
}

func (l *LinkedList) removeDuplicates() {
	current := l.head
	for current != nil {
		temp := current.next
		for temp != nil {
			if temp.value == current.value {
				fmt.Printf("found duplicates for %s and %s \n", current.ToString(), temp.ToString())
				l.removeNode(temp)
				break
			}
			temp = temp.next
		}
		current = current.next
	}
}

func (l *LinkedList) print(debug bool) {
	elem := l.head
	fmt.Println("all items:")
	for elem != nil {
		if debug {
			var flags string
			if elem == l.head {
				flags = flags + "H"
			}
			if elem == l.tail {
				flags = flags + "T"
			}
			fmt.Printf("[%s]%s\n", flags, elem.value)
		} else {
			fmt.Println(elem.value)
		}
		elem = elem.next
	}
}

func main() {
	debug := true
	myList := LinkedList{}
	myList.add("item1")
	myList.add("item2")
	myList.add("item3")
	myList.add("item4")
	myList.add("item3")
	myList.add("item5")
	myList.add("item5")
	myList.add("item4")
	myList.print(debug)
	myList.removeDuplicates()
	myList.print(debug)

	/*
		fmt.Println("------ remove item 4 ------")
		myList.remove("item4")
		myList.print(debug)
		//como fazer uma lista encadeada em golang?
		fmt.Println("------ remove item 1 ------")
		myList.remove("item1")
		myList.print(debug)

		fmt.Println("------ remove item 5 ------")
		myList.remove("item5")
		myList.print(debug)
		fmt.Println("------ remove item 3 ------")
		myList.remove("item3")
		myList.print(debug)
		fmt.Println("------ remove item 2 ------")
		myList.remove("item2")
		myList.print(debug)
	*/
}