day20

day20/day.go

@@ -0,0 +1,54 @@
+package day20
+
+import (
+	"math"
+	"tools"
+)
+
+func Part1(puzzle tools.AoCPuzzle) interface{} {
+	target := puzzle.GetInputArrayInt()[0]
+
+	presents := 0
+	houseNumber := 0
+	for presents < target {
+		houseNumber++
+		divisor := tools.NewSet()
+		for i := 1; i <= int(math.Sqrt(float64(houseNumber))); i++ {
+			if houseNumber%i == 0 {
+				divisor.Add(i)
+				divisor.Add(houseNumber / i)
+			}
+		}
+		presents = 0
+		for v := range divisor {
+			presents += v.(int) * 10
+		}
+	}
+
+	return houseNumber
+}
+
+func Part2(puzzle tools.AoCPuzzle) interface{} {
+	target := puzzle.GetInputArrayInt()[0]
+
+	presents := 0
+	houseNumber := 0
+	for presents < target {
+		houseNumber++
+		divisor := tools.NewSet()
+
+		for i := 1; i <= int(math.Sqrt(float64(houseNumber))); i++ {
+			if houseNumber%i == 0 {
+				divisor.Add(houseNumber / i)
+			}
+		}
+		presents = 0
+		for v := range divisor {
+			if houseNumber/v.(int) < 50 {
+				presents += v.(int) * 11
+			}
+		}
+	}
+
+	return houseNumber
+}

inputs/20

@@ -0,0 +1 @@
+34000000

inputs/20_test

@@ -0,0 +1 @@
+4650

main.go

@@ -20,6 +20,7 @@ import (
 	"aoc2015/day17"
 	"aoc2015/day18"
 	"aoc2015/day19"
+	"aoc2015/day20"
 	"flag"
 	"fmt"
 	"os"
@@ -56,6 +57,7 @@ func initDayFunctions() {
 		17: {1: day17.Part1, 2: day17.Part2},
 		18: {1: day18.Part1, 2: day18.Part2},
 		19: {1: day19.Part1, 2: day19.Part2},
+		20: {1: day20.Part1, 2: day20.Part2},
 	}
 }