complete 2162.py

zeta_python/completed/2162.py

@@ -0,0 +1,72 @@
+import sys
+from collections import Counter
+
+input = sys.stdin.readline
+
+
+def ccw(p1, p2, p3):
+    # fmt: off
+    s = (p1[0] * p2[1] + p2[0] * p3[1] + p3[0] * p1[1]) \
+        - (p1[1] * p2[0] + p2[1] * p3[0] + p3[1] * p1[0])
+    # fmt: on
+    if s > 0:
+        return 1
+    elif s == 0:
+        return 0
+    else:
+        return -1
+
+
+class LinesGroup:
+    def __init__(self, N: int, lines: list):
+        self.__lines = lines
+        self.__parents = [i for i in range(N)]
+        for i in range(N):
+            for j in range(i + 1, N):
+                if self.intersect(i, j):
+                    self.merge(i, j)
+        self.__roots = [self.root(i) for i in range(N)]
+        self.__counters: Counter = Counter(self.__roots)
+
+    def intersect(self, a: int, b: int) -> bool:
+        a: tuple[int] = self.__lines[a]
+        b: tuple[int] = self.__lines[b]
+        p1, p2 = (a[0], a[1]), (a[2], a[3])
+        p3, p4 = (b[0], b[1]), (b[2], b[3])
+        p1p2 = ccw(p1, p2, p3) * ccw(p1, p2, p4)
+        p3p4 = ccw(p3, p4, p1) * ccw(p3, p4, p2)
+        if p1p2 == 0 and p3p4 == 0:
+            if p1 > p2:
+                p1, p2 = p2, p1
+            if p3 > p4:
+                p3, p4 = p4, p3
+            return p3 <= p2 and p1 <= p4
+        return p1p2 <= 0 and p3p4 <= 0
+
+    def merge(self, a, b):
+        rb, ra = self.root(b), self.root(a)
+        if ra < rb:
+            self.__parents[rb] = ra
+        else:
+            self.__parents[ra] = rb
+
+    def root(self, e) -> int:
+        node = e
+        while node != self.__parents[node]:
+            node = self.__parents[node]
+        return node
+
+    @property
+    def num_groups(self):
+        return len(self.__counters)
+
+    @property
+    def num_max(self):
+        return self.__counters.most_common(1)[0][1]
+
+
+if __name__ == "__main__":
+    N = int(input())
+    groups = LinesGroup(N, [tuple(map(int, input().split())) for _ in range(N)])
+    print(groups.num_groups)
+    print(groups.num_max)