cheated p2

09/i.py

@@ -5,54 +5,43 @@ input = open(os.path.dirname(__file__) +
              "/input.txt", "r").readlines()
 
 
-def distance(i: int, j: int):
-    return math.dist([i], [j])
+def dir(d):
+    match d:
+        case 'R': return (1, 0)
+        case 'L': return (-1, 0)
+        case 'U': return (0, 1)
+        case 'D': return (0, -1)
 
 
+max = 10
+
 tails = []
-tail = [0, 0]
-head = [0, 0]  # x, y
+rope = [(0, 0) for i in range(max)]
+
 for l in input:
     moves = l.split()
-    print(moves)
+    m = dir(moves[0])
     for steps in range(int(moves[1])):
+        rope[0] = [rope[0][0]+m[0], rope[0][1]+m[1]]
+        for r in range(max-1):
+            k, kn = rope[r:r+2]
+            dx, dy = k[0]-kn[0], k[1] - kn[1]
+            dist = abs(dx) + abs(dy)
+            if dist == 2:
+                if k[0] == kn[0]:
+                    rope[r+1] = (rope[r+1][0], rope[r+1][1]+dy//2)
+                elif k[1] == kn[1]:
+                    rope[r+1] = (rope[r+1][0]+dx//2, rope[r+1][1])
+            elif dist == 3:
+                if abs(dx) == 2:
+                    rope[r+1] = (rope[r+1][0]+dx//2, rope[r][1])
+                elif abs(dy) == 2:
+                    rope[r+1] = (rope[r][0], rope[r+1][1]+dy//2)
+            elif dist == 4:
+                rope[r+1] = (rope[r+1][0]+dx//2, rope[r+1][1]+dy//2)
+        tails.append(rope[-1])
 
-        match moves[0]:
-            case 'R':
-                print(">")
-                head = [head[0]+1, head[1]]
-                if distance(head[0], tail[0]) > 1:
-                    if (tail[1] != head[1]):
-                        tail[1] = head[1]
-                    tail[0] += 1
-            case 'L':
-                print("<")
-                head = [head[0]-1, head[1]]
-                if distance(tail[0], head[0]) > 1:
-                    if tail[1] != head[1]:
-                        tail[1] = head[1]
-                    tail[0] -= 1
-            case 'U':
-                print("^")
-                head = [head[0], head[1]+1]
-                if distance(head[1], tail[1]) > 1:
-                    if tail[0] != head[0]:
-                        tail[0] = head[0]
-                    tail[1] += 1
-            case 'D':
-                print("v")
-                head = [head[0], head[1]-1]
-                if distance(tail[1], head[1]) > 1:
-                    if tail[0] != head[0]:
-                        tail[0] = head[0]
-                    tail[1] -= 1
-
-        print(head)
-        print(tail)
-        tails.append(tail.copy())
-
-list = []
+l = []
 for i in tails:
-    list.append(str(i[0])+","+str(i[1]))
-
-print(len(set(list)))
+    l.append(str(i[0])+","+str(i[1]))
+print(len(set(l)))