From 7518efc103548d5976c9de4570f7c91916d593bc Mon Sep 17 00:00:00 2001
From: ptrcnull <git@ptrcnull.me>
Date: Mon, 6 Dec 2021 07:41:51 +0100
Subject: [PATCH] 06: part1+2

---
 6/input     |  1 +
 6/part1.go  | 33 +++++++++++++++++++++++++++++++++
 6/part2.go  | 39 +++++++++++++++++++++++++++++++++++++++
 6/testinput |  1 +
 4 files changed, 74 insertions(+)
 create mode 100644 6/input
 create mode 100644 6/part1.go
 create mode 100644 6/part2.go
 create mode 100644 6/testinput

diff --git a/6/input b/6/input
new file mode 100644
index 0000000..3d35529
--- /dev/null
+++ b/6/input
@@ -0,0 +1 @@
+3,1,5,4,4,4,5,3,4,4,1,4,2,3,1,3,3,2,3,2,5,1,1,4,4,3,2,4,2,4,1,5,3,3,2,2,2,5,5,1,3,4,5,1,5,5,1,1,1,4,3,2,3,3,3,4,4,4,5,5,1,3,3,5,4,5,5,5,1,1,2,4,3,4,5,4,5,2,2,3,5,2,1,2,4,3,5,1,3,1,4,4,1,3,2,3,2,4,5,2,4,1,4,3,1,3,1,5,1,3,5,4,3,1,5,3,3,5,4,2,3,4,1,2,1,1,4,4,4,3,1,1,1,1,1,4,2,5,1,1,2,1,5,3,4,1,5,4,1,3,3,1,4,4,5,3,1,1,3,3,3,1,1,5,4,2,5,1,1,5,5,1,4,2,2,5,3,1,1,3,3,5,3,3,2,4,3,2,5,2,5,4,5,4,3,2,4,3,5,1,2,2,4,3,1,5,5,1,3,1,3,2,2,4,5,4,2,3,2,3,4,1,3,4,2,5,4,4,2,2,1,4,1,5,1,5,4,3,3,3,3,3,5,2,1,5,5,3,5,2,1,1,4,2,2,5,1,4,3,3,4,4,2,3,2,1,3,1,5,2,1,5,1,3,1,4,2,4,5,1,4,5,5,3,5,1,5,4,1,3,4,1,1,4,5,5,2,1,3,3
diff --git a/6/part1.go b/6/part1.go
new file mode 100644
index 0000000..de354c5
--- /dev/null
+++ b/6/part1.go
@@ -0,0 +1,33 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	var fishes []int
+
+	s := bufio.NewScanner(os.Stdin)
+	s.Scan()
+	for _, fishStr := range strings.Split(s.Text(), ",") {
+		fish, _ := strconv.Atoi(fishStr)
+		fishes = append(fishes, fish)
+	}
+
+	for x := 0; x < 80; x++ {
+		for i := range fishes {
+			if fishes[i] == 0 {
+				fishes[i] = 6
+				fishes = append(fishes, 8)
+			} else {
+				fishes[i]--
+			}
+		}
+	}
+
+	fmt.Println(len(fishes))
+}
diff --git a/6/part2.go b/6/part2.go
new file mode 100644
index 0000000..d91576f
--- /dev/null
+++ b/6/part2.go
@@ -0,0 +1,39 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	// https://en.wiktionary.org/wiki/fishes#English
+	fishes := map[int]int{}
+
+	s := bufio.NewScanner(os.Stdin)
+	s.Scan()
+	for _, fishStr := range strings.Split(s.Text(), ",") {
+		fish, _ := strconv.Atoi(fishStr)
+		fishes[fish]++
+	}
+
+	for x := 0; x < 256; x++ {
+		newFishes := map[int]int{}
+		// handle usual decrements
+		for i := 8; i > 0; i-- {
+			newFishes[i-1] = fishes[i]
+		}
+		// handle the new fishes
+		newFishes[6] += fishes[0]
+		newFishes[8] += fishes[0]
+		fishes = newFishes
+	}
+
+	sum := 0
+	for _, count := range fishes {
+		sum += count
+	}
+	fmt.Println(sum)
+}
diff --git a/6/testinput b/6/testinput
new file mode 100644
index 0000000..a7af2b1
--- /dev/null
+++ b/6/testinput
@@ -0,0 +1 @@
+3,4,3,1,2
\ No newline at end of file