2017-day4: comparing strings

2017/day04/main.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/alexchao26/advent-of-code-go/util"
+)
+
+func main() {
+	var part int
+	flag.IntVar(&part, "part", 1, "part 1 or 2")
+	flag.Parse()
+	fmt.Println("Running part", part)
+
+	if part == 1 {
+		ans := part1(util.ReadFile("./input.txt"))
+		fmt.Println("Output:", ans)
+	} else {
+		ans := part2(util.ReadFile("./input.txt"))
+		fmt.Println("Output:", ans)
+	}
+}
+
+func part1(input string) int {
+	phrases := parseInput(input)
+	var valid int
+	for _, phrase := range phrases {
+		seen := map[string]bool{}
+		valid++ // include by default, remove if it is not valid
+		for _, word := range phrase {
+			// if word is a duplicate, decrement valid & break out
+			if seen[word] {
+				valid--
+				break
+			}
+			seen[word] = true
+		}
+	}
+
+	return valid
+}
+
+func part2(input string) int {
+	phrases := parseInput(input)
+	var valid int
+	for _, phrase := range phrases {
+		seen := map[string]bool{}
+		valid++ // include by default, remove if it is not valid
+		for _, word := range phrase {
+			sortedWord := orderCharacters(word)
+			// if word is a duplicate, decrement valid & break out
+			if seen[sortedWord] {
+				valid--
+				break
+			}
+			seen[sortedWord] = true
+		}
+	}
+
+	return valid
+}
+
+func orderCharacters(str string) string {
+	chars := strings.Split(str, "")
+	sort.Strings(chars)
+	return strings.Join(chars, "")
+}
+
+func parseInput(input string) (ans [][]string) {
+	lines := strings.Split(input, "\n")
+	for _, l := range lines {
+		ans = append(ans, strings.Split(l, " "))
+	}
+	return ans
+}

2017/day04/main_test.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/alexchao26/advent-of-code-go/util"
+)
+
+func Test_part1(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  int
+	}{
+		{"actual", util.ReadFile("input.txt"), 466},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := part1(tt.input); got != tt.want {
+				t.Errorf("part1() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_part2(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  int
+	}{
+		{"actual", util.ReadFile("input.txt"), 251},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := part2(tt.input); got != tt.want {
+				t.Errorf("part2() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}