day24

Author: Oscar Franzén

digidis-go/day24/day24.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"strings"
+)
+
+var ports [][2]int
+var used map[int]bool
+
+func main() {
+	data, _ := ioutil.ReadFile("input.txt")
+	rows := strings.Split(string(data), "\n")
+	var a, b int
+	for _, r := range rows {
+		fmt.Sscanf(r, "%d/%d", &a, &b)
+		ports = append(ports, [2]int{a, b})
+	}
+
+	used = make(map[int]bool)
+	for i, p := range ports {
+		if p[0] == 0 {
+			fmt.Printf("starting from %v\n", p)
+			solve(i, p[1])
+		}
+		if p[1] == 0 {
+			fmt.Printf("starting from %v\n", p)
+			solve(i, p[0])
+		}
+	}
+
+	fmt.Printf("Maxium strength %v\n", maxS)
+	fmt.Printf("Maxium strength and length %v\n", maxSL)
+}
+
+var maxS, maxL, maxSL int
+
+func solve(start int, next int) {
+	used[start] = true
+	for i, p := range ports {
+		if !used[i] && p[0] == next {
+			solve(i, p[1])
+		}
+		if !used[i] && p[1] == next {
+			solve(i, p[0])
+		}
+	}
+	s, l := calc()
+	maxS = max(maxS, s)
+	maxL = max(maxL, l)
+	if l == maxL && s > maxSL {
+		maxSL = s
+	}
+	used[start] = false
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func calc() (s, l int) {
+	for i := range used {
+		if used[i] {
+			l++
+			s = s + ports[i][0] + ports[i][1]
+		}
+	}
+	return
+}

digidis-go/day24/input.txt

@@ -0,0 +1,54 @@
+48/5
+25/10
+35/49
+34/41
+35/35
+47/35
+34/46
+47/23
+28/8
+27/21
+40/11
+22/50
+48/42
+38/17
+50/33
+13/13
+22/33
+17/29
+50/0
+20/47
+28/0
+42/4
+46/22
+19/35
+17/22
+33/37
+47/7
+35/20
+8/36
+24/34
+6/7
+7/43
+45/37
+21/31
+37/26
+16/5
+11/14
+7/23
+2/23
+3/25
+20/20
+18/20
+19/34
+25/46
+41/24
+0/33
+3/7
+49/38
+47/22
+44/15
+24/21
+10/35
+6/21
+14/50