From 1aa90ce2504fa5ca46dbc78218aa14915da96004 Mon Sep 17 00:00:00 2001
From: Ang Chin Han <ang.chin.han@gmail.com>
Date: Tue, 10 Dec 2024 14:50:55 +0800
Subject: [PATCH] feat(angch/2024-10): Initial

---
 angch/2024-10/main.go  | 72 ++++++++++++++++++++++++++++++++++++++++++
 angch/2024-10/test.txt |  8 +++++
 2 files changed, 80 insertions(+)
 create mode 100644 angch/2024-10/main.go
 create mode 100644 angch/2024-10/test.txt

diff --git a/angch/2024-10/main.go b/angch/2024-10/main.go
new file mode 100644
index 0000000..956b691
--- /dev/null
+++ b/angch/2024-10/main.go
@@ -0,0 +1,72 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"time"
+)
+
+func day10(file string) (part1, part2 int) {
+	f, err := os.Open(file)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer f.Close()
+	scanner := bufio.NewScanner(f)
+
+	mm := map[[2]int]int{}
+	mm2 := map[int]map[[2]int]bool{}
+
+	y := 0
+	for scanner.Scan() {
+		t := scanner.Text()
+
+		for x, k := range t {
+			c := int(k - '0')
+			mm[[2]int{x, y}] = c
+			_, ok := mm2[c]
+			if !ok {
+				mm2[c] = make(map[[2]int]bool)
+			}
+			mm2[c][[2]int{x, y}] = true
+		}
+		y++
+	}
+
+	for v, _ := range mm2[0] {
+		paths := map[[2]int]int{v: 1}
+		for h := 1; h <= 9; h++ {
+			npaths := map[[2]int]int{}
+			for v, _ := range paths {
+				for p, _ := range mm2[h] {
+					dx := max(p[0], v[0]) - min(p[0], v[0])
+					dy := max(p[1], v[1]) - min(p[1], v[1])
+					if dx+dy == 1 {
+						npaths[p] += paths[v]
+					}
+				}
+			}
+			paths = npaths
+		}
+		part1 += len(paths)
+		for _, v := range paths {
+			part2 += v
+		}
+	}
+
+	return
+}
+
+func main() {
+	log.SetFlags(log.Lshortfile | log.LstdFlags)
+	t1 := time.Now()
+	part1, part2 := day10("test.txt")
+	fmt.Println(part1, part2)
+	if part1 != 36 || part2 != 81 {
+		log.Fatal("Test failed ", part1, part2)
+	}
+	fmt.Println(day10("input.txt"))
+	fmt.Println("Elapsed time:", time.Since(t1))
+}
diff --git a/angch/2024-10/test.txt b/angch/2024-10/test.txt
new file mode 100644
index 0000000..7bb1248
--- /dev/null
+++ b/angch/2024-10/test.txt
@@ -0,0 +1,8 @@
+89010123
+78121874
+87430965
+96549874
+45678903
+32019012
+01329801
+10456732
\ No newline at end of file