feat(2017): refactor day 4

Refactored Day 4 of 2017 to use the common framework. Successfully migrated solution and integrated it into the runner.

Author: markkovari

2017/days/4/day04.go

@@ -0,0 +1,63 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/markkovari/advent_of_code/aoc-go-common"
+)
+
+type Day04 struct{}
+
+func (d Day04) Part1(input string) string {
+	countValid := 0
+	for _, line := range strings.Split(input, "\n") {
+		if line == "" { continue }
+		words := strings.Fields(line)
+		frequency := make(map[string]int)
+		valid := true
+		for _, word := range words {
+			frequency[word]++
+			if frequency[word] > 1 {
+				valid = false
+				break
+			}
+		}
+		if valid { countValid++ }
+	}
+	return fmt.Sprintf("%d", countValid)
+}
+
+func (d Day04) Part2(input string) string {
+	countValid := 0
+	for _, line := range strings.Split(input, "\n") {
+		if line == "" { continue }
+		words := strings.Fields(line)
+		if !hasAnagram(words) {
+			countValid++
+		}
+	}
+	return fmt.Sprintf("%d", countValid)
+}
+
+func hasAnagram(words []string) bool {
+	sortedWords := make([]string, len(words))
+	for i, word := range words {
+		chars := strings.Split(word, "")
+		sort.Strings(chars)
+		sortedWords[i] = strings.Join(chars, "")
+	}
+	for i := 0; i < len(sortedWords); i++ {
+		for j := i + 1; j < len(sortedWords); j++ {
+			if sortedWords[i] == sortedWords[j] {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func main() {
+	common.Run(2017, 4, Day04{})
+}