Initial commit

python/Algorithms/convex_hull.py

@@ -0,0 +1,29 @@
+def convex_hull(points):
+    points = sorted(set(points))
+
+    if len(points) <= 1:
+        return points
+
+    def hull(points):
+        def cross(a, b, c):
+            return (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0])
+
+        res = []
+        for p in points:
+            while len(res) >= 2 and cross(res[-2], res[-1], p) >= 0:
+                res.pop()
+            res.append(p)
+        return res
+
+    return hull(points)[:-1] + hull(reversed(points))[:-1]
+
+
+def test():
+    import random
+
+    assert convex_hull([(0, 0), (0, 0)]) == [(0, 0)]
+    assert convex_hull([(i // 10, i % 10) for i in range(100)]) == [(0, 0), (0, 9), (9, 9), (9, 0)]
+    print(len(convex_hull([(random.randint(0, 10000), random.randint(0, 10000)) for i in range(10000)])))
+
+
+test()