aoc2023/day-7/util.go

package main

import (
	"bufio"
	"log"
	"os"
	"sort"
	"strconv"
	"strings"
)

// readlines reads lines from stdin.
// Then it returns them as an array of strings
func readlines() []string {
	lines := []string{}

	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		lines = append(lines, scanner.Text())
	}

	if err := scanner.Err(); err != nil {
		log.Fatal(err)
	}

	return lines
}

func parselines(lines []string) {
	for _, line := range lines {
		splitted := strings.Split(line, " ")
		n, _ := strconv.Atoi(splitted[1])
		hands = append(hands, newHand(splitted[0], n))
	}
}

// matches checks for number of matching cards in hand
func matches(cards string) map[rune]int {
	m := map[rune]int{}
	for _, r := range cards {
		_, ok := m[r]
		if !ok {
			m[r] = strings.Count(cards, string(r))
		}
	}

	return m
}

// contains returns true if a slice of elements contains a given element
func contains[T comparable](elems []T, v T) bool {
	for _, s := range elems {
		if v == s {
			return true
		}
	}
	return false
}

// indexOf returns the index of an element in a slice
func indexOf(collection []rune, elem rune) int {
	for i, x := range collection {
		if x == elem {
			return i
		}
	}
	return -1
}

func containsChar(s string, c string) bool {
	for _, v := range s {
		if c == string(v) {
			return true
		}
	}
	return false
}

func sortByKindAndStrength(strength []rune) {
	sort.Slice(hands, func(i, j int) bool {
		if hands[i].kind() == hands[j].kind() {
			for k := range hands[i].cards {
				if hands[i].cards[k] == hands[j].cards[k] {
					continue
				}
				return indexOf(strength, rune(hands[i].cards[k])) > indexOf(strength, rune(hands[j].cards[k]))
			}
		}
		return hands[i].kind() < hands[j].kind()
	})
}