aoc24/day11/main.go

package main

import (
	"fmt"
	"strconv"
	"strings"

	"git.mstar.dev/mstar/aoc24/util"
	"git.mstar.dev/mstar/goutils/other"
	"git.mstar.dev/mstar/goutils/sliceutils"
)

type TreeNode struct {
	Left, Right *TreeNode
	Value       uint64
	IsLeaf      bool
}

func lineToNumbers(line string) []uint64 {
	return sliceutils.Map(
		strings.Split(line, " "),
		func(t string) uint64 { return other.Must(strconv.ParseUint(t, 10, 64)) },
	)
}

func numbersIntoTree(numbers []uint64) *TreeNode {
	switch len(numbers) {
	case 1:
		return &TreeNode{
			Left: &TreeNode{
				Left:   nil,
				Right:  nil,
				Value:  numbers[0],
				IsLeaf: true,
			},
			Right:  nil,
			Value:  0,
			IsLeaf: false,
		}
	case 2:
		return &TreeNode{
			Left: &TreeNode{
				Left:   nil,
				Right:  nil,
				Value:  numbers[0],
				IsLeaf: true,
			},
			Right: &TreeNode{
				Left:   nil,
				Right:  nil,
				Value:  numbers[1],
				IsLeaf: true,
			},
			Value:  0,
			IsLeaf: false,
		}
	default:
		l, r := splitListIntoTwo(numbers)
		return &TreeNode{
			Left:   numbersIntoTree(l),
			Right:  numbersIntoTree(r),
			Value:  0,
			IsLeaf: false,
		}
	}
}

func splitListIntoTwo[S ~[]T, T any](s S) (S, S) {
	middle := len(s) / 2
	left := S{}
	right := S{}

	for i, v := range s {
		if i < middle {
			left = append(left, v)
		} else {
			right = append(right, v)
		}
	}
	return left, right
}

func (n *TreeNode) Advance() {
	if n.IsLeaf {
		// 1. 0 -> 1
		// 2. len("num") % 2 == 0 -> num[len("num")/2:], num[:len("num")/2]
		//   2424 -> 24, 24; 435892 -> 435, 892
		// 3. x -> x * 2024
		switch {
		case n.Value == 0:
			n.Value = 1
		case len(strconv.FormatUint(n.Value, 10))%2 == 0:
			str := strconv.FormatUint(n.Value, 10)
			left := string([]rune(str)[:len(str)/2])
			right := string([]rune(str)[len(str)/2:])
			n.IsLeaf = false
			n.Left = &TreeNode{
				Left:   nil,
				Right:  nil,
				Value:  other.Must(strconv.ParseUint(left, 10, 64)),
				IsLeaf: true,
			}
			n.Right = &TreeNode{
				Left:   nil,
				Right:  nil,
				Value:  other.Must(strconv.ParseUint(right, 10, 64)),
				IsLeaf: true,
			}
		default:
			n.Value *= 2024
		}
	} else {
		if n.Left != nil {
			n.Left.Advance()
		}
		if n.Right != nil {
			n.Right.Advance()
		}
	}
}

func (n *TreeNode) String() string {
	if n.IsLeaf {
		return fmt.Sprint(n.Value)
	} else {
		if n.Right != nil {
			return fmt.Sprintf("%s %s", n.Left, n.Right)
		} else {
			return fmt.Sprint(n.Left)
		}
	}
}

func (n *TreeNode) Count() uint64 {
	if n.IsLeaf {
		return 1
	} else {
		if n.Right != nil {
			return n.Left.Count() + n.Right.Count()
		} else {
			return n.Left.Count()
		}
	}
}

func main() {
	nums := lineToNumbers(strings.TrimSpace(string(util.LoadFileFromArgs())))
	tree := numbersIntoTree(nums)
	// fmt.Printf("%#v\n", tree.Right)
	for range 25 {
		tree.Advance()
	}
	fmt.Printf("Task 1: %d\n", tree.Count())
	var accCheck uint64 = 0
	for _, num := range nums {
		accCheck += Advance(num, 0, 25)
	}
	fmt.Printf("Check 1: %d\n", accCheck)
	// for range 50 {
	// 	tree.Advance()
	// }
	// fmt.Printf("Task 2: %d\n", tree.Count())
	// resetCache()
	var acc uint64 = 0
	for _, num := range nums {
		acc += Advance(num, 0, 75)
	}
	// addChan := make(chan uint64, 1)
	// wg := sync.WaitGroup{}
	// go func() {
	// 	for v := range addChan {
	// 		acc += v
	// 	}
	// }()
	// for _, num := range nums {
	// 	wg.Add(1)
	// 	go func() {
	// 		addChan <- Advance(num, 0, 75)
	// 		wg.Done()
	// 	}()
	// }
	// wg.Wait()
	// close(addChan)
	fmt.Printf("Task 2: %d\n", acc)
}