Day 10 Python solutions

Author: creideiki

10-1.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python
+
+import numpy
+
+
+class Map:
+    def __init__(self, input):
+        self.height = len(input)
+        self.width = len(input[0])
+        self.trailheads = []
+        self.peaks = []
+        self.map = numpy.zeros((self.height, self.width), dtype=numpy.uint8)
+        for y in range(self.height):
+            for x in range(self.width):
+                match input[y][x]:
+                    case '.':
+                        self.map[y, x] = 255
+                    case '0':
+                        self.map[y, x] = 0
+                        self.trailheads.append((y, x))
+                    case '9':
+                        self.map[y, x] = 9
+                        self.peaks.append((y, x))
+                    case _:
+                        self.map[y, x] = int(input[y][x])
+
+    def trace(self, y, x, visited):
+        if visited[y, x] == 1:
+            return 0
+
+        visited[y, x] = 1
+        cur_height = self.map[y, x]
+
+        if cur_height == 9:
+            return 1
+
+        score = 0
+        if y + 1 < self.height and self.map[y + 1, x] == cur_height + 1:
+            score += self.trace(y + 1, x, visited)
+        if y - 1 >= 0 and self.map[y - 1, x] == cur_height + 1:
+            score += self.trace(y - 1, x, visited)
+        if x + 1 < self.width and self.map[y, x + 1] == cur_height + 1:
+            score += self.trace(y, x + 1, visited)
+        if x - 1 >= 0 and self.map[y, x - 1] == cur_height + 1:
+            score += self.trace(y, x - 1, visited)
+        return score
+
+    def hike(self):
+        score = 0
+        for t in self.trailheads:
+            score += self.trace(t[0], t[1],
+                                numpy.zeros((self.height, self.width), dtype=numpy.uint8))
+        return score
+
+
+map = Map([row.strip() for row in open('10.input').readlines()])
+print(map.hike())

10-2.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+
+import numpy
+
+
+class Map:
+    def __init__(self, input):
+        self.height = len(input)
+        self.width = len(input[0])
+        self.trailheads = []
+        self.peaks = []
+        self.map = numpy.zeros((self.height, self.width), dtype=numpy.uint8)
+        for y in range(self.height):
+            for x in range(self.width):
+                match input[y][x]:
+                    case '.':
+                        self.map[y, x] = 255
+                    case '0':
+                        self.map[y, x] = 0
+                        self.trailheads.append((y, x))
+                    case '9':
+                        self.map[y, x] = 9
+                        self.peaks.append((y, x))
+                    case _:
+                        self.map[y, x] = int(input[y][x])
+
+    def trace(self, y, x, visited):
+        if (y, x) in visited:
+            return 0
+
+        cur_height = self.map[y, x]
+
+        if cur_height == 9:
+            return 1
+
+        score = 0
+        if y + 1 < self.height and self.map[y + 1, x] == cur_height + 1:
+            score += self.trace(y + 1, x, visited + [(y, x)])
+        if y - 1 >= 0 and self.map[y - 1, x] == cur_height + 1:
+            score += self.trace(y - 1, x, visited + [(y, x)])
+        if x + 1 < self.width and self.map[y, x + 1] == cur_height + 1:
+            score += self.trace(y, x + 1, visited + [(y, x)])
+        if x - 1 >= 0 and self.map[y, x - 1] == cur_height + 1:
+            score += self.trace(y, x - 1, visited + [(y, x)])
+        return score
+
+    def hike(self):
+        score = 0
+        for t in self.trailheads:
+            score += self.trace(t[0], t[1], [])
+        return score
+
+
+map = Map([row.strip() for row in open('10.input').readlines()])
+print(map.hike())