pgoultiaev/aoc2017

package main

import (
    "bufio"
    "fmt"
    "log"
    "os"
    "strings"
)

func main() {
    file, err := os.Open("12.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer file.Close()

    scanner := bufio.NewScanner(file)

    nodes := map[string]map[string]bool{}

    for scanner.Scan() {
        link := scanner.Text()

        i := strings.Index(link, "<->")
        keyString := link[0 : i-1]

        valStrings := link[i+4:]
        valStringsSplit := strings.Split(valStrings, ", ")

        //fmt.Printf("found key: %s, val %+v\n", keyString, valStringsSplit)
        nodesToAdd := append(valStringsSplit, keyString)

        for _, val := range nodesToAdd {
            for _, node := range nodesToAdd {
                child, ok := nodes[val]

                if !ok {
                    child = map[string]bool{}
                    nodes[val] = child
                }
                nodes[val][node] = true
            }
        }
    }

    set0 := traverse("0", map[string]bool{}, nodes, map[string]bool{})
    independentGroups := getIndependentGroups(nodes)

    fmt.Printf("Part one: %d\n", len(set0))
    fmt.Printf("Part two: %d\n", independentGroups)
}

func getIndependentGroups(nodes map[string]map[string]bool) (groupCount int) {
    nodeList := nodes

    for k := range nodeList {
        set := traverse(k, map[string]bool{}, nodes, map[string]bool{})
        for k := range set {
            delete(nodeList, k)
        }
        groupCount++
    }
    return groupCount
}

func traverse(n string, set0 map[string]bool, nodes map[string]map[string]bool, visited map[string]bool) map[string]bool {
    if len(visited) == len(nodes) {
        return set0
    }
    for k := range nodes[n] {
        set0[k] = true

        if visited[k] != true {
            visited[k] = true
            traverse(k, set0, nodes, visited)
        }
    }
    return set0
}