Day10

day10/day10.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"AoC2020/helper"
+	"fmt"
+	"os"
+	"sort"
+)
+
+func main() {
+	args := os.Args[1:]
+	input, err := helper.GetInput(args[0])
+	if err != nil {
+		fmt.Println(err)
+	}
+	numbers, err := helper.MapToNumber(input)
+	if err != nil {
+		fmt.Println(err)
+	}
+	part2(numbers)
+}
+
+func part2(numbers []int)  {
+	sort.Ints(numbers)
+	numbers = prependInt(numbers,0)
+	numbers = append(numbers,numbers[len(numbers)-1]+3)
+	fmt.Printf("%v \n",numbers)
+	possibilities := make([][3]int, len(numbers))
+	possibilities[len(numbers)-1] = [3]int{0,0,1}
+	for i:= len(numbers)-1; i >= 0; i-- {
+		diff := 0
+		j := 1
+		for diff <= 3 && i+j<len(numbers){
+			diff = numbers[i+j] - numbers[i]
+			switch diff {
+			case 1:
+				possibilities[i][0] = sum(possibilities[i+j])
+			case 2:
+				possibilities[i][1] = sum(possibilities[i+j])
+			case 3:
+				possibilities[i][2] = sum(possibilities[i+j])
+			}
+			j++
+		}
+	}
+	fmt.Printf("%v \n",possibilities)
+	fmt.Printf("%d \n",sum(possibilities[0]))
+}
+
+func part1(numbers []int)  {
+	sort.Ints(numbers)
+	diffCounter := make([]int, 3)
+	numbers = prependInt(numbers,0)
+	numbers = append(numbers,numbers[len(numbers)-1]+3)
+	fmt.Printf("%v \n",numbers)
+	for i:= 0; i < len(numbers)-1; i++ {
+		diffCounter[numbers[i+1] - numbers[i]-1]++
+	}
+	fmt.Printf("%v \n",diffCounter)
+	fmt.Print(diffCounter[0] * diffCounter[2])
+}
+
+func prependInt(x []int, y int) []int {
+	x = append(x, 0)
+	copy(x[1:], x)
+	x[0] = y
+	return x
+}
+
+func sum(array [3]int) int {
+	result := 0
+	for _, v := range array {
+		result += v
+	}
+	return result
+}
+

day10/day10Input.txt

@@ -0,0 +1,106 @@
+66
+7
+73
+162
+62
+165
+157
+158
+137
+125
+138
+59
+36
+40
+94
+95
+13
+35
+136
+96
+156
+155
+24
+84
+42
+171
+142
+3
+104
+149
+83
+129
+19
+122
+68
+103
+74
+118
+20
+110
+54
+127
+88
+31
+135
+26
+126
+2
+51
+91
+16
+65
+128
+119
+67
+48
+111
+29
+49
+12
+132
+17
+41
+166
+75
+146
+50
+30
+1
+164
+112
+34
+18
+72
+97
+145
+11
+117
+58
+78
+152
+90
+172
+163
+89
+107
+45
+37
+79
+159
+141
+105
+10
+115
+69
+170
+25
+100
+80
+4
+85
+169
+106
+57
+116
+23

day10/day10Test.txt

@@ -0,0 +1,11 @@
+16
+10
+15
+5
+1
+11
+7
+19
+6
+12
+4

day10/day10Test2.txt

@@ -0,0 +1,31 @@
+28
+33
+18
+42
+31
+14
+46
+20
+48
+47
+24
+23
+49
+45
+19
+38
+39
+11
+1
+32
+25
+35
+8
+17
+7
+9
+4
+2
+34
+10
+3