Day 3

day3/so1.py

@@ -0,0 +1,38 @@
+NORTH = "^"
+SOUTH = "v"
+WEST = "<"
+EAST = ">"
+
+def move(pos, d):
+    if d == NORTH:
+        pos[1] += 1
+    if d == SOUTH:
+        pos[1] -= 1
+    if d == WEST:
+        pos[0] -= 1
+    if d == EAST:
+        pos[0] += 1
+
+def visit(s):
+    pos = [0,0]
+    visits = set()
+    visits.add((pos[0], pos[1]))
+
+    for c in s:
+        move(pos, c)
+        visits.add((pos[0], pos[1]))
+
+    return len(visits)
+
+def test():
+    assert visit(">") == 2
+    assert visit("^>v<") == 4
+    assert visit("^v^v^v^v^v") == 2
+
+def solution():
+    with open("in1") as puzzle:
+        l = puzzle.read()
+        return visit(l)
+
+if __name__ == "__main__":
+    print(f"Houses: {solution()}")

day3/so2.py

@@ -0,0 +1,51 @@
+NORTH = "^"
+SOUTH = "v"
+WEST = "<"
+EAST = ">"
+
+class Santa:
+    def __init__(self, visits): # visits is a ref
+        self.pos = [0,0]
+        self.visits = visits
+        self.visits.add((self.pos[0], self.pos[1]))
+
+    def move(self, d):
+        if d == NORTH:
+            self.pos[1] += 1
+        if d == SOUTH:
+            self.pos[1] -= 1
+        if d == WEST:
+            self.pos[0] -= 1
+        if d == EAST:
+            self.pos[0] += 1
+
+    def visit(self, d):
+        self.move(d)
+        self.visits.add((self.pos[0], self.pos[1]))
+
+def visit(l):
+    visits = set()
+
+    robo = Santa(visits)
+    santa = Santa(visits)
+    for i,c in enumerate(l):
+        if i%2 == 0:
+            santa.visit(c)
+        else:
+            robo.visit(c)
+
+    return len(visits)
+
+
+def test():
+    assert visit("^v") == 3
+    assert visit("^>v<") == 3
+    assert visit("^v^v^v^v^v") == 11
+
+def solution():
+    with open("in2") as puzzle:
+        l = puzzle.read()
+        return visit(l)
+
+if __name__ == "__main__":
+    print(f"Houses: {solution()}")