Day 6: Part 1 and 2

six/day_six.go

@@ -0,0 +1,105 @@
+package six
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+)
+
+type group struct {
+	questions []string
+}
+
+type flight struct {
+	groups []group
+}
+
+func (g *group) uniqueQuestion() int {
+	questions := map[string]bool{}
+
+	for _, answers := range g.questions {
+		for _, q := range answers {
+			if !questions[string(q)] {
+				questions[string(q)] = true
+			}
+		}
+	}
+
+	return len(questions)
+}
+
+func (g *group) consensusQuestions() int {
+	questions := map[string][]bool{}
+
+	for _, answers := range g.questions {
+		for _, q := range answers {
+			questions[string(q)] = append(questions[string(q)], true)
+		}
+	}
+
+	consensus := 0
+	for _, q := range questions {
+		if len(q) == len(g.questions) {
+			consensus++
+		}
+	}
+
+	return consensus
+}
+
+func (f *flight) load(filename string) error {
+	file, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	var g *group
+	for scanner.Scan() {
+		if scanner.Text() == "" {
+			// Blank line means we have moved on to the next passport
+			if g != nil {
+				f.groups = append(f.groups, *g)
+				g = nil
+			}
+			continue
+		}
+
+		if g == nil {
+			g = &group{}
+		}
+
+		g.questions = append(g.questions, scanner.Text())
+	}
+	// commit the last passport if there isn't a blank line
+	if g != nil {
+		f.groups = append(f.groups, *g)
+	}
+
+	return nil
+}
+
+// PartOne Find the sum of all the unique questions in all groups
+func PartOne() string {
+	f := flight{}
+	f.load("six/customs.txt")
+	sum := 0
+	for _, g := range f.groups {
+		sum += g.uniqueQuestion()
+	}
+
+	return fmt.Sprintf("The sum of all the unique questions in all groups is %d", sum)
+}
+
+// PartTwo Find the sum of all the consensus questions in all groups
+func PartTwo() string {
+	f := flight{}
+	f.load("six/customs.txt")
+	sum := 0
+	for _, g := range f.groups {
+		sum += g.consensusQuestions()
+	}
+
+	return fmt.Sprintf("The sum of all the consensus questions in all groups is %d", sum)
+}