add 2024/day1-day5 python

2024/04/main.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8; py-indent-offset: 4 -*-
+
+# Author: Sebastian Mark
+# CC-BY-SA (https://creativecommons.org/licenses/by-sa/4.0/deed.de)
+
+# pylint: disable=missing-module-docstring,missing-function-docstring,consider-using-f-string
+
+
+def readinput() -> list:
+    with open("input", "r", encoding="utf-8") as file:
+        lines = file.readlines()
+    return lines
+
+
+def find_xmas(grid: list[list], x: int, y: int) -> int:
+    height = len(grid) - 1
+    width = len(grid[0]) - 1
+
+    count = 0
+    for searchstring in ["XMAS", "SAMX"]:
+        # horizontal right
+        if x + 3 <= width:
+            found = sum(grid[y][x + i] == searchstring[i] for i in range(4))
+            if found == 4:
+                count += 1
+
+        # vertical down
+        if y + 3 <= height:
+            found = sum(grid[y + i][x] == searchstring[i] for i in range(4))
+            if found == 4:
+                count += 1
+
+        # diagonal down right
+        if y + 3 <= height and x + 3 <= width:
+            found = sum(grid[y + i][x + i] == searchstring[i] for i in range(4))
+            if found == 4:
+                count += 1
+
+        # diagonal down left
+        if y + 3 <= height and x - 3 >= 0:
+            found = sum(grid[y + i][x - i] == searchstring[i] for i in range(4))
+            if found == 4:
+                count += 1
+
+    return count
+
+
+def find_cross_mass(grid: list[list], x: int, y: int) -> int:
+    # check clockwise for
+    # M.M
+    # .A.
+    # S.S
+    # then rotate the outer ring clockwise and check again
+    for searchstring in ["MMSS", "SMMS", "SSMM", "MSSM"]:
+        found = (
+            grid[y - 1][x - 1] == searchstring[0]
+            and grid[y - 1][x + 1] == searchstring[1]
+            and grid[y + 1][x + 1] == searchstring[2]
+            and grid[y + 1][x - 1] == searchstring[3]
+        )
+        if found:
+            return 1
+
+    return 0
+
+
+def main():
+    grid = readinput()
+
+    count = 0
+    for y, _ in enumerate(grid):
+        for x, _ in enumerate(grid[0]):
+            pos = grid[y][x]
+            if pos in ["X", "S"]:
+                count += find_xmas(grid, x, y)
+    print("XMAS count: %d" % count)
+
+    count = 0
+    for y in range(1, len(grid) - 1):
+        for x in range(1, len(grid[0]) - 1):
+            pos = grid[y][x]
+            if pos == "A":
+                count += find_cross_mass(grid, x, y)
+    print("X-MAS count: %d" % count)
+
+
+if __name__ == "__main__":
+    main()