2024 Dec 06th

Python/2024/06/main.py

@@ -0,0 +1,51 @@
+input = open("input", 'r')
+
+# d = [line for line in input]
+# d = [[val for val in line.strip()] for line in input]
+d = {(complex(x,y)): c for y,line in enumerate(input) for x,c in enumerate(line)}
+
+guard = 0
+
+for pos,char in d.items():
+    if char == "^":
+        guard = pos
+        break
+
+def step(pos,dir):
+    npos = pos + dir
+    if npos not in d:
+        return -1,-1
+    elif d[npos] == "#":
+        return pos,(dir*1j)
+    else:
+        return npos,dir
+
+def run():
+    pos = guard
+    sposs = set([pos])
+    dir = -1j
+    loop = set([(pos,dir)])
+    while pos != -1:
+        pos,dir = step(pos,dir)
+        if (pos,dir) in loop:
+            return -1
+        if pos == -1:
+            break
+        sposs.add(pos)
+        loop.add((pos,dir))
+    return len(sposs)
+
+def run2():
+    sm = 0
+    for pos,char in d.items():
+        if char != ".":
+            continue
+        d[pos] = "#"
+        if run(True) == -1:
+            sm += 1
+        d[pos] = "."
+    return sm
+
+
+print(run())
+print(run2())