day03

day03/day03.go

@@ -0,0 +1,74 @@
+package day03
+
+import (
+	"aoc2015/aoclib"
+)
+
+func Part1(puzzle aoclib.Puzzle) interface{} {
+	x, y := 0, 0
+	houses := make(map[int]map[int]bool)
+
+	for _, c := range puzzle.GetInputArray()[0] {
+		switch c {
+		case '^':
+			x--
+		case '<':
+			y--
+		case '>':
+			y++
+		case 'v':
+			x++
+		}
+
+		if _, ok := houses[x]; !ok {
+			houses[x] = make(map[int]bool)
+		}
+
+		houses[x][y] = true
+	}
+
+	houseCount := 0
+	for x := range houses {
+		houseCount += len(houses[x])
+	}
+
+	return houseCount
+}
+
+func Part2(puzzle aoclib.Puzzle) interface{} {
+	x, y := [2]int{0, 0}, [2]int{0, 0}
+	turn := 0
+	houses := make(map[int]map[int]bool)
+
+	for _, c := range puzzle.GetInputArray()[0] {
+		switch c {
+		case '^':
+			x[turn]--
+		case '<':
+			y[turn]--
+		case '>':
+			y[turn]++
+		case 'v':
+			x[turn]++
+		}
+
+		if _, ok := houses[x[turn]]; !ok {
+			houses[x[turn]] = make(map[int]bool)
+		}
+
+		houses[x[turn]][y[turn]] = true
+
+		if turn == 0 {
+			turn = 1
+		} else {
+			turn = 0
+		}
+	}
+
+	houseCount := 0
+	for x := range houses {
+		houseCount += len(houses[x])
+	}
+
+	return houseCount
+}

inputs/3_test

@@ -0,0 +1 @@
+>^>v<^v^v^v^v^v

main.go

@@ -4,6 +4,7 @@ import (
 	"aoc2015/aoclib"
 	"aoc2015/day01"
 	"aoc2015/day02"
+	"aoc2015/day03"
 	"flag"
 	"fmt"
 	"os"
@@ -26,6 +27,9 @@ func initDayFunctions() {
 	dayFunctions[2] = make(map[int]func(puzzle aoclib.Puzzle) interface{})
 	dayFunctions[2][1] = day02.Part1
 	dayFunctions[2][2] = day02.Part2
+	dayFunctions[3] = make(map[int]func(puzzle aoclib.Puzzle) interface{})
+	dayFunctions[3][1] = day03.Part1
+	dayFunctions[3][2] = day03.Part2
 }
 
 func execute(thisDay int) {