Day 3

day03/common/rucksack.go

@@ -0,0 +1,57 @@
+package common
+
+import (
+  "bufio"
+)
+
+type Compartment struct {
+  items []int
+}
+
+func (compartment *Compartment) AddItem(itemName byte) {
+  if itemName < 'a' {
+    compartment.items = append(compartment.items, int(itemName - 'A' + 27))
+  } else {
+    compartment.items = append(compartment.items, int(itemName - 'a' + 1))
+  }
+}
+
+func (compartment Compartment) GetItems() []int {
+  return compartment.items
+}
+
+func (compartment Compartment) ContainsItem(item int) bool {
+  for _, cItem := range compartment.items {
+    if item == cItem {
+      return true
+    }
+  }
+  return false
+}
+
+type Rucksack struct {
+  compartments [2]Compartment
+}
+
+func (rucksack Rucksack) GetCompartment(id int) Compartment {
+  return rucksack.compartments[id-1]
+}
+
+func Parse(scanner bufio.Scanner) []Rucksack {
+  rucksacks := []Rucksack{}
+
+  for scanner.Scan() {
+    currentRucksack := Rucksack{}
+    line := scanner.Text()
+    compartmentLength := len(line) / 2
+    for i := 0; i < compartmentLength; i++ {
+      currentRucksack.compartments[0].AddItem(line[i])
+    }
+    for i := 0; i < compartmentLength; i++ {
+      currentRucksack.compartments[1].AddItem(line[compartmentLength+i])
+    }
+    rucksacks = append(rucksacks, currentRucksack)
+  }
+
+  return rucksacks
+}

day03/ex1/main.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+  "bufio"
+  "fmt"
+  "os"
+  "aoc2022/day03/common"
+)
+
+func main() {
+  rucksacks := common.Parse(*bufio.NewScanner(os.Stdin))
+  sum := 0
+
+  for _, rucksack := range rucksacks {
+    for _, item := range rucksack.GetCompartment(1).GetItems() {
+      if rucksack.GetCompartment(2).ContainsItem(item) {
+        sum += item
+        break
+      }
+    }
+  }
+
+  fmt.Println(sum)
+}

day03/ex2/main.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+  "bufio"
+  "fmt"
+  "os"
+  "aoc2022/day03/common"
+)
+
+func main() {
+  rucksacks := common.Parse(*bufio.NewScanner(os.Stdin))
+  sum := 0
+
+  for i := 0; i < len(rucksacks); i+=3 {
+    rucksack := rucksacks[i]
+    commonItems := append(rucksack.GetCompartment(1).GetItems(), rucksack.GetCompartment(2).GetItems()...)
+    for j := 1; j <= 2; j++ {
+      for k := 0; k < len(commonItems); k++ {
+        item := commonItems[k]
+        if !rucksacks[i+j].GetCompartment(1).ContainsItem(item) && !rucksacks[i+j].GetCompartment(2).ContainsItem(item) {
+          commonItems = append(commonItems[:k], commonItems[k+1:]...)
+          k--
+        }
+      }
+    }
+    sum += commonItems[0]
+  }
+
+  fmt.Println(sum)
+}