🚩

VERSION

@@ -1 +1 @@
-🐷
+🚩

y2023/p18.py

@@ -1,94 +1,130 @@
-def render(graph, default='.'):
-    xmin, *_, xmax = sorted(int(p.real) for p in graph)
-    ymin, *_, ymax = sorted(int(p.imag) for p in graph)
-    out = ''
-    for y in range(ymin, ymax + 1):
-        for x in range(xmin, xmax + 1):
-            out += graph.get(complex(x, y), default)
-        out += '\n'
-    return out
-
-
-def connected_components(graph):
-    groups = []
-    while graph:
-        seen = set()
-        edge = {graph.pop()}
-        while edge:
-            seen |= edge
-            edge = {pp + ss for pp in edge for ss in [1, -1, 1j, -1j] if pp + ss in graph if pp + ss not in seen}
-        groups.append(seen)
-        graph -= seen
-    return groups
-
-
-def get_solid(walls):
-    xmin, *_, xmax = sorted(int(p.real) for p in walls)
-    ymin, *_, ymax = sorted(int(p.imag) for p in walls)
-
-    mesh = {complex(x, y) for x in range(xmin, xmax + 1) for y in range(ymin, ymax + 1)}
-    void = mesh - walls
-    groups = connected_components(void)
-    border = lambda p: p.real in {xmin, xmax} or p.imag in {ymin, ymax}
-    inside = {p for g in groups if not any(border(p) for p in g) for p in g}
-    solid = inside | walls
-    return solid
-
-
-def solve1():
-    pos = 0
-    walls = {pos}
-    for line in text.splitlines():
-        d, n, _ = line.split()
-        dirx = 1j ** 'RDLU'.index(d)
-        goal = pos + dirx * int(n)
-        while pos != goal:
-            pos += dirx
-            walls.add(pos)
-    solid = get_solid(walls)
-    print(len(solid))
-
-
-def solve2():
-    points = {0}
-    pos = 0
-    for line in text.splitlines():
-        _, _, rest = line.split()
-        n, d = int(rest[1:-1][1:][:5], 16), 'RDLU'[int(rest[-2])]
-        dirx = 1j ** 'RDLU'.index(d)
-        pos += dirx * int(n)
-        points.add(pos)
-
-    b2s = {
-        complex(bx, by) + dx + dy: 3 * complex(sx, sy) + dx + dy
-        for sx, bx in enumerate(sorted({p.real for p in points}))
-        for sy, by in enumerate(sorted({p.imag for p in points}))
-        for dx in [-1, 0, 1] for dy in [-1j, 0, 1j]
-    }
-    s2b = {v: k for k, v in b2s.items()}
-
-    pos, smallpos = 0, b2s[0]
-    walls = {smallpos}
-    for line in text.splitlines():
-        d, n, rest = line.split()
-        n, d = int(rest[1:-1][1:][:5], 16), 'RDLU'[int(rest[-2])]
-        dirx = 1j ** 'RDLU'.index(d)
-        pos += dirx * int(n)
-        goal = b2s[pos]
-        while smallpos != goal:
-            smallpos += dirx
-            walls.add(smallpos)
-
-    solid = get_solid(walls)
-
-    out = 0
-    for smallpos in solid:
-        c1, c2 = s2b[smallpos], s2b[smallpos + 1 + 1j]
-        w, h = (c2 - c1).real, (c2 - c1).imag
-        out += int(w * h)
-    print(out)
+def perimeter(pts):
+    n = 0
+    for i in range(len(pts)):
+        dist = pts[i - 1] - pts[i]
+        n += abs(dist.real) + abs(dist.imag)
+    return int(n)
+
+
+def area(pts):
+    # shoelace method
+    a = 0
+    for i in range(len(pts)):
+        p1, p2 = pts[i - 1], pts[i]
+        a += p1.real * p2.imag - p2.real * p1.imag
+    return int(a / 2)
 
 
 text = open(0).read()
-solve1()
-solve2()
+
+pts = [0]
+for line in text.splitlines():
+    d, n, _ = line.split()
+    n = int(n)
+    d = 1j ** 'RDLU'.index(d)
+    pts.append(pts[-1] + d * n)
+print(area(pts) + perimeter(pts) // 2 + 1)
+
+pts = [0]
+for line in text.splitlines():
+    _, _, s = line.split()
+    n = int(s[2:7], 16)
+    d = 1j ** int(s[7])
+    pts.append(pts[-1] + d * n)
+print(area(pts) + perimeter(pts) // 2 + 1)
+
+
+# def render(graph, default='.'):
+#     xmin, *_, xmax = sorted(int(p.real) for p in graph)
+#     ymin, *_, ymax = sorted(int(p.imag) for p in graph)
+#     out = ''
+#     for y in range(ymin, ymax + 1):
+#         for x in range(xmin, xmax + 1):
+#             out += graph.get(complex(x, y), default)
+#         out += '\n'
+#     return out
+
+
+# def connected_components(graph):
+#     groups = []
+#     while graph:
+#         seen = set()
+#         edge = {graph.pop()}
+#         while edge:
+#             seen |= edge
+#             edge = {pp + ss for pp in edge for ss in [1, -1, 1j, -1j] if pp + ss in graph if pp + ss not in seen}
+#         groups.append(seen)
+#         graph -= seen
+#     return groups
+
+
+# def get_solid(walls):
+#     xmin, *_, xmax = sorted(int(p.real) for p in walls)
+#     ymin, *_, ymax = sorted(int(p.imag) for p in walls)
+
+#     mesh = {complex(x, y) for x in range(xmin, xmax + 1) for y in range(ymin, ymax + 1)}
+#     void = mesh - walls
+#     groups = connected_components(void)
+#     border = lambda p: p.real in {xmin, xmax} or p.imag in {ymin, ymax}
+#     inside = {p for g in groups if not any(border(p) for p in g) for p in g}
+#     solid = inside | walls
+#     return solid
+
+
+# def solve1():
+#     pos = 0
+#     walls = {pos}
+#     for line in text.splitlines():
+#         d, n, _ = line.split()
+#         dirx = 1j ** 'RDLU'.index(d)
+#         goal = pos + dirx * int(n)
+#         while pos != goal:
+#             pos += dirx
+#             walls.add(pos)
+#     solid = get_solid(walls)
+#     print(len(solid))
+
+
+# def solve2():
+#     points = {0}
+#     pos = 0
+#     for line in text.splitlines():
+#         _, _, rest = line.split()
+#         n, d = int(rest[1:-1][1:][:5], 16), 'RDLU'[int(rest[-2])]
+#         dirx = 1j ** 'RDLU'.index(d)
+#         pos += dirx * int(n)
+#         points.add(pos)
+
+#     b2s = {
+#         complex(bx, by) + dx + dy: 3 * complex(sx, sy) + dx + dy
+#         for sx, bx in enumerate(sorted({p.real for p in points}))
+#         for sy, by in enumerate(sorted({p.imag for p in points}))
+#         for dx in [-1, 0, 1] for dy in [-1j, 0, 1j]
+#     }
+#     s2b = {v: k for k, v in b2s.items()}
+
+#     pos, smallpos = 0, b2s[0]
+#     walls = {smallpos}
+#     for line in text.splitlines():
+#         d, n, rest = line.split()
+#         n, d = int(rest[1:-1][1:][:5], 16), 'RDLU'[int(rest[-2])]
+#         dirx = 1j ** 'RDLU'.index(d)
+#         pos += dirx * int(n)
+#         goal = b2s[pos]
+#         while smallpos != goal:
+#             smallpos += dirx
+#             walls.add(smallpos)
+
+#     solid = get_solid(walls)
+
+#     out = 0
+#     for smallpos in solid:
+#         c1, c2 = s2b[smallpos], s2b[smallpos + 1 + 1j]
+#         w, h = (c2 - c1).real, (c2 - c1).imag
+#         out += int(w * h)
+#     print(out)
+
+
+# text = open(0).read()
+# solve1()
+# solve2()