package main

import (
	"fmt"
	"sort"
	"strconv"
	"strings"
)

type Day1Input struct {
	column1 []int64
	column2 []int64
}

func Day1Parse(lines []string) (*Day1Input, error) {
	column1 := make([]int64, len(lines))
	column2 := make([]int64, len(lines))

	for i, line := range lines {
		parts := strings.SplitN(line, " ", 2)

		column1_value, err := strconv.ParseInt(strings.TrimSpace(parts[0]), 10, 0)
		if err != nil {
			return nil, err
		}


		column2_value, err := strconv.ParseInt(strings.TrimSpace(parts[1]), 10, 0)
		if err != nil {
			return nil, err
		}

		column1[i] = column1_value
		column2[i] = column2_value
	}

	parsed := Day1Input{
		column1,
		column2,
	}

	return &parsed, nil
}

func Day1Part1(lines []string) (error) {
	input, err := Day1Parse(lines)
	if err != nil {
		return err
	}

	sort.Slice(input.column1, func(i, j int) bool {
		return input.column1[i] < input.column1[j]
	})

	sort.Slice(input.column2, func(i, j int) bool {
		return input.column2[i] < input.column2[j]
	})

	var answer int64 = 0
	for i := range len(input.column1) {
		if input.column1[i] > input.column2[i] {
			answer += input.column1[i] - input.column2[i];
		} else {
			answer += input.column2[i] - input.column1[i];
		}
	}

	fmt.Println(answer)

	return nil
}

func Day1Part2(lines []string) (error) {
	input, err := Day1Parse(lines)
	if err != nil {
		return err
	}

	var answer int64 = 0
	for _, value1 := range input.column1 {
		var count int64 = 0
		for _, value2 := range input.column2 {
			if value1 == value2 {
				count += 1
			}
		}
		answer += count * value1
	}

	fmt.Println(answer)

	return nil
}