Bebert day 10 part 1

day-10/input/bebert.txt

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+#..#.#.#.######..#.#...##
+##.#..#.#..##.#..######.#
+.#.##.#..##..#.#.####.#..
+.#..##.#.#..#.#...#...#.#
+#...###.##.##..##...#..#.
+##..#.#.#.###...#.##..#.#
+###.###.#.##.##....#####.
+.#####.#.#...#..#####..#.
+.#.##...#.#...#####.##...
+######.#..##.#..#.#.#....
+###.##.#######....##.#..#
+.####.##..#.##.#.#.##...#
+##...##.######..##..#.###
+...###...#..#...#.###..#.
+.#####...##..#..#####.###
+.#####..#.#######.###.##.
+#...###.####.##.##.#.##.#
+.#.#.#.#.#.##.#..#.#..###
+##.#.####.###....###..##.
+#..##.#....#..#..#.#..#.#
+##..#..#...#..##..####..#
+....#.....##..#.##.#...##
+.##..#.#..##..##.#..##..#
+.##..#####....#####.#.#.#
+#..#..#..##...#..#.#.#.##

day-10/part-1/bebert.pyx

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+import cython
+
+DEF GRID_W = 40
+DEF GRID_H = 40
+DEF GRID_LEN = 1600
+
+@cython.cdivision(True)
+cdef int gcd(int a, int b):
+    cdef int r
+    while b != 0:
+        r = a % b
+        a, b = b, r
+    return a
+
+@cython.cdivision(True)
+cdef void step(char* g, int x, int y, int dx, int dy):
+    if g[(y + dy) * GRID_W + (x + dx)] == 0:
+        return
+
+    cdef int gcd_dx_dy = gcd(dx if dx > 0 else -dx, dy if dy > 0 else -dy)
+    cdef int reduced_dx = dx // gcd_dx_dy
+    cdef int reduced_dy = dy // gcd_dx_dy
+    g[(y + dy) * GRID_W + (x + dx)] = 0
+    g[(y + reduced_dy) * GRID_W + (x + reduced_dx)] = 1
+
+# cdef void print_grid(char* g):
+#     cdef str pg = ''
+#     cdef int i
+#     for i in range(GRID_LEN):
+#         if i % GRID_W == 0:
+#             pg += "\n"
+#         pg += ".#x-"[g[i]]
+#     print(pg)
+
+cpdef int run(s):
+    cdef int i, x, y, count
+    cdef str a
+
+    cdef char[1600] grid
+    cdef char[1600] cur_grid
+    for i in range(GRID_LEN):
+        grid[i] = 0
+
+    for y, line in enumerate(s.splitlines()):
+        for x, a in enumerate(line):
+            if a == "#":
+                grid[y * GRID_W + x] = 1
+
+    cdef int max_ast = 0
+    cdef int max_x = 0
+    cdef int max_y = 0
+
+    # print_grid(grid)
+
+    for y in range(GRID_H):
+        for x in range(GRID_W):
+            if grid[y * GRID_W + x] == 0:
+                continue
+
+            # reset
+            for i in range(GRID_LEN):
+                cur_grid[i] = grid[i]
+
+            cur_grid[y * GRID_W + x] = 0
+
+            # Zone 1
+            dy = 0
+            for dx in range(1, GRID_W - x):
+                step(cur_grid, x, y, dx, dy)
+
+            for dy in range(1, GRID_H - y):
+                for dx in range(0, GRID_W - x):
+                    step(cur_grid, x, y, dx, dy)
+
+            # Zone 2
+            for dy in range(0, GRID_H - y):
+                for dx in range(-1, -x-1, -1):
+                    step(cur_grid, x, y, dx, dy)
+
+            # Zone 3
+            for dy in range(-1, -y-1, -1):
+                for dx in range(0, GRID_W - x):
+                    step(cur_grid, x, y, dx, dy)
+
+            # Zone 4
+            for dy in range(-1, -y-1, -1):
+                for dx in range(-1, -x-1, -1):
+                    step(cur_grid, x, y, dx, dy)
+
+            count = 0
+            for i in range(GRID_LEN):
+                if cur_grid[i] == 1:
+                    count += 1
+
+            if count > max_ast:
+                max_ast = count
+                max_x = x
+                max_y = y
+
+            # if x == 5 and y == 3:
+            #     cur_grid[3 * GRID_W + 5] = 2
+            #     print_grid(cur_grid)
+            #     print(f"count: {count}")
+            #     print(f"max_ast: {max_ast}")
+
+    # print(f"Max (x, y): ({max_x}, {max_y}) -> {max_ast}")
+    return max_ast