Added solutions for 18th day: snailfish arithmetic

2021/18/second.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"git.adyxax.org/aoc/2021/18/pairs"
+)
+
+func main() {
+	max := 0
+	parser := pairs.NewParser(os.Stdin)
+	pairs := make([]*pairs.Pair, 0)
+	for {
+		pair, err := parser.Parse()
+		if err != nil {
+			break
+		}
+		pairs = append(pairs, pair)
+	}
+	l := len(pairs)
+	for i := 0; i < l; i++ {
+		for j := 0; j < l; j++ {
+			if i == j {
+				continue
+			}
+			p1 := pairs[i].DeepCopy()
+			p2 := pairs[j].DeepCopy()
+			if m := p1.Add(p2).Magnitude(); max < m {
+				max = m
+			}
+		}
+	}
+	fmt.Println(max)
+}