dedup.go

package main

import "fmt"

type Node struct {
	Data int
	Next *Node
}

// deduplicates a linked list
func dedupsWithStore(node *Node) {

	seenValues := map[int]bool{}

	// loop through nodes while there is still a next
	for n := node; n.Next != nil; n = n.Next {

		if ok := seenValues[n.Next.Data]; !ok {
			seenValues[n.Next.Data] = true
		} else {
			fmt.Printf("duplicate value: %d\n", n.Next.Data)
			n.Next = n.Next.Next
		}
		fmt.Printf("value: %d\n", n.Data)
	}
}

func main() {

	n1 := Node{Data: 5}
	n2 := Node{Data: 4, Next: &n1}
	n3 := Node{Data: 5, Next: &n2}
	n4 := Node{Data: 3, Next: &n3}
	n5 := Node{Data: 2, Next: &n4}

	dedupsWithStore(&n5)
}