package main

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

// Given a list of paired integers with columns representing two groups,
// compute the total distance between pairs in the sorted lists.
func main() {

	// open input file

	input, err := os.ReadFile("input")
	if err != nil {
		fmt.Println(err)
	}

	// Walk the list and create two lists, left and right
	left, right := extractLists(string(input))

	// Sort left and right
	sort.Slice(left, func(i, j int) bool {
		return left[i] < left[j]
	})
	sort.Slice(right, func(i, j int) bool {
		return right[i] < right[j]
	})

	// lFreqMap := frequencyMap(left)
	rFreqMap := frequencyMap(right)

	// Walk through left and compare each element to its pair in right

	differenceTotal := 0
	scoreTotal := 0
	for idx, val := range left {
		var l, r int
		l = val
		r = right[idx]

		// Sum distance between elements
		difference := l - r
		score := l * rFreqMap[l]

		// Take absolute value
		if difference < 0 {
			difference = -difference
		}
		differenceTotal += difference
		scoreTotal += score
	}

	// Return total distance

	fmt.Println(differenceTotal)
	fmt.Println(scoreTotal)
}

func frequencyMap(slice []int) map[int]int {
	frequency := make(map[int]int) // val -> score

	for _, val := range slice {
		frequency[val] = frequency[val] + 1
	}

	return frequency
}

func extractLists(input string) ([]int, []int) {
	var left, right []int
	for _, val := range strings.Split(input, "\n") {
		// fmt.Println(idx)
		t := strings.Fields(val)
		if len(t) < 2 {
			continue
		}
		l, err := strconv.Atoi(t[0])
		if err != nil {
			panic("aaa")
		}
		left = append(left, l)
		r, err := strconv.Atoi(t[1])
		if err != nil {
			panic("bbb")
		}
		right = append(right, r)
	}
	return left, right
}