Day 4

day04/common/section.go

@@ -0,0 +1,48 @@
+package common
+
+import (
+	"bufio"
+	"strconv"
+	"strings"
+)
+
+type Assignment struct {
+  start int
+  end int
+}
+
+func (assignment Assignment) Contains(other Assignment) bool {
+  return assignment.start <= other.start && assignment.end >= other.end
+}
+
+type AssignmentPair struct {
+  assignments [2]Assignment
+}
+
+func (pair AssignmentPair) OverlapsFully() bool {
+  return pair.assignments[0].Contains(pair.assignments[1]) || pair.assignments[1].Contains(pair.assignments[0])
+}
+
+func (pair AssignmentPair) Overlaps() bool {
+  return (pair.assignments[0].start >= pair.assignments[1].start && pair.assignments[0].start <= pair.assignments[1].end) ||
+         (pair.assignments[1].start >= pair.assignments[0].start && pair.assignments[1].start <= pair.assignments[0].end)
+}
+
+func Parse(scanner bufio.Scanner) []AssignmentPair {
+  pairs := []AssignmentPair{}
+
+  for scanner.Scan() {
+    line := scanner.Text()
+    splittedPair := strings.Split(line, ",")
+    currentAssignmentPair := AssignmentPair{}
+    for i := 0; i < 2; i++ {
+      splittedAssignment := strings.Split(splittedPair[i], "-")
+      start, _ := strconv.Atoi(splittedAssignment[0])
+      end, _ := strconv.Atoi(splittedAssignment[1])
+      currentAssignmentPair.assignments[i] = Assignment{start, end}
+    }
+    pairs = append(pairs, currentAssignmentPair)
+  }
+
+  return pairs
+}

day04/ex1/main.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+  "bufio"
+  "fmt"
+  "os"
+  "aoc2022/day04/common"
+)
+
+func main() {
+  assignmentPairs := common.Parse(*bufio.NewScanner(os.Stdin))
+  sum := 0
+
+  for _, assignmentPair := range assignmentPairs {
+    if assignmentPair.OverlapsFully() {
+      sum++
+    }
+  }
+
+  fmt.Println(sum)
+}

day04/ex2/main.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+  "bufio"
+  "fmt"
+  "os"
+  "aoc2022/day04/common"
+)
+
+func main() {
+  assignmentPairs := common.Parse(*bufio.NewScanner(os.Stdin))
+  sum := 0
+
+  for _, assignmentPair := range assignmentPairs {
+    if assignmentPair.Overlaps() {
+      sum++
+    }
+  }
+
+  fmt.Println(sum)
+}