diff --git a/scratch/facebook/intersecting-linked-lists.py b/scratch/facebook/intersecting-linked-lists.py new file mode 100644 index 000000000..80ac01daf --- /dev/null +++ b/scratch/facebook/intersecting-linked-lists.py @@ -0,0 +1,34 @@ +class LinkedList(object): + def __init__(self, x): + self.val = x + self.next = None + + def __repr__(self): + if self.next: + return "{} -> {}".format(self.val, self.next) + return "{}".format(self.val) + +def find_intersection(a, b): + init_a, init_b = a, b + + while a != b: + a = a.next if a.next else init_b + b = b.next if b.next else init_a + + return a + +# make A... +e1 = LinkedList(5) +d1 = LinkedList(2); d1.next = e1 +c1 = LinkedList(3); c1.next = d1 # shared +b1 = LinkedList(1); b1.next = c1 # shared +a1 = LinkedList(4); a1.next = b1 # shared + +# make B... +c2 = LinkedList(1); c2.next = c1 +b2 = LinkedList(5); b2.next = c2 +a2 = LinkedList(6); a2.next = b2 + +print(a1) +print(a2) +print(find_intersection(a1, a2).val)