05

2021/05/README.md

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+# 05
+
+Description
+
+<details>
+  <summary>Solutions</summary>
+  <ol>
+    <li>5608</li>
+    <li>20299</li>
+  </ol>
+</details>

2021/05/python/main.py

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+#!/usr/bin/env python
+
+from os.path import join, dirname
+from typing import List
+
+# Day 05
+
+# Common
+
+
+def read_input(filename):
+    data = join(dirname(__file__), '..', filename)
+    with open(data) as f:
+        return f.read().strip()
+
+
+class Point:
+    def __init__(self, x, y):
+        self.x = x
+        self.y = y
+
+    def __repr__(self) -> str:
+        return f'({self.x},{self.y})'
+
+    @staticmethod
+    def parse(raw: str):
+        x, y = raw.strip().split(',')
+        return Point(int(x), int(y))
+
+
+class Line:
+    def __init__(self, a: Point, b: Point):
+        self.a = a
+        self.b = b
+
+    def is_straight(self) -> bool:
+        return self.a.x == self.b.x or self.a.y == self.b.y
+
+    def is_diagonal(self) -> bool:
+        return abs(self.a.x - self.b.x) == abs(self.a.y - self.b.y)
+
+    def get_points(self) -> List[Point]:
+        if self.is_straight():
+            if self.a.x == self.b.x:
+                return [
+                    Point(self.a.x, y) for y
+                    in range(min(self.a.y, self.b.y), max(self.a.y, self.b.y) + 1)
+                ]
+            else:
+                return [
+                    Point(x, self.a.y) for x
+                    in range(min(self.a.x, self.b.x), max(self.a.x, self.b.x) + 1)
+                ]
+        else:
+            dx = self.a.x - self.b.x
+            dy = self.a.y - self.b.y
+            sign_x = 1 if dx < 0 else -1
+            sign_y = 1 if dy < 0 else -1
+            return [
+                Point(self.a.x + sign_x * i, self.a.y + sign_y * i)
+                for i in range(abs(dx) + 1)
+            ]
+
+    def __repr__(self) -> str:
+        return f'{self.a} → {self.b}'
+
+    @staticmethod
+    def parse(raw: str):
+        a, b = raw.strip().split('->')
+        return Line(Point.parse(a), Point.parse(b))
+
+
+class Scan:
+    def __init__(self, lines: List[Line]):
+        self.lines = lines
+
+    def keep_straight(self):
+        self.lines = [line for line in self.lines if line.is_straight()]
+
+    def keep_straight_and_diagonal(self):
+        self.lines = [
+            line for line in self.lines
+            if line.is_straight() or line.is_diagonal()
+        ]
+
+    def matrix(self) -> List[List[int]]:
+        x_max = max(max(line.a.x, line.b.x) for line in self.lines)
+        y_max = max(max(line.a.y, line.b.y) for line in self.lines)
+        matrix = [
+            [0 for _ in range(x_max + 1)]
+            for _ in range(y_max + 1)
+        ]
+        for line in self.lines:
+            for point in line.get_points():
+                matrix[point.y][point.x] += 1
+        return matrix
+
+    def plot(self) -> str:
+        output = '\n'.join([
+            ' '.join(str(x) for x in row)
+            for row in self.matrix()
+        ])
+        return output.replace('0', '.')
+
+    def danger(self) -> int:
+        matrix = self.matrix()
+        return sum(
+            sum(1 for x in row if x > 1)
+            for row in matrix
+        )
+
+    @ staticmethod
+    def parse(raw: str):
+        return Scan([Line.parse(line) for line in raw.strip().split('\n')])
+
+
+test = read_input('test.txt')
+data = read_input('input.txt')
+
+# 1
+print('1.')
+scan = Scan.parse(test)
+scan.keep_straight()
+print(scan.plot())
+print('Test: ', scan.danger())
+
+scan = Scan.parse(data)
+scan.keep_straight()
+print('Real: ', scan.danger())
+
+# 2
+print('\n2.')
+
+scan = Scan.parse(test)
+scan.keep_straight_and_diagonal()
+print(scan.plot())
+print('Test: ', scan.danger())
+
+scan = Scan.parse(data)
+scan.keep_straight_and_diagonal()
+print('Real: ', scan.danger())