Solution Day 9

2022/Day9/Day9.py

@@ -0,0 +1,25 @@
+def do_moves(moves, rope_len):
+    xs = [0] * rope_len
+    ys = [0] * rope_len
+    visited = {(xs[-1], ys[-1])}
+
+    for (mx, my), distance in moves:
+        for _ in range(distance):
+            xs[0] += mx
+            ys[0] += my
+            for i in range(rope_len - 1):
+                dx = xs[i + 1] - xs[i]
+                dy = ys[i + 1] - ys[i]
+                if abs(dx) == 2 or abs(dy) == 2:
+                    xs[i + 1] = xs[i] + int(dx / 2)
+                    ys[i + 1] = ys[i] + int(dy / 2)
+            visited.add((xs[-1], ys[-1]))
+
+    return len(visited)
+
+
+if __name__ == '__main__':
+    offsets = {'L': (-1, 0), 'R': (1, 0), 'D': (0, -1), 'U': (0, 1)}
+    moves = [(offsets[line[0]], int(line[1:])) for line in open("input.txt", "r")]
+    print("Part 1:", do_moves(moves, 2))
+    print("Part 2:", do_moves(moves, 10))