Print in Order — LeetCode 1114 Python Solution

The problem

Suppose we have a class: public class Foo { public void first() { print("first"); } public void second() { print("second"); } public void third() { print("third"); } } The same instance of Foo will be passed to three different threads. Thread A will call first(), thread B will call second(), and thread C will call third().

Example

public class Foo {
  public void first() { print("first"); }
  public void second() { print("second"); }
  public void third() { print("third"); }
}

Python solution

class Foo:
    def __init__(self):
        self.l2 = threading.Lock()
        self.l3 = threading.Lock()
        self.l2.acquire()
        self.l3.acquire()

    def first(self, printFirst: 'Callable[[], None]') -> None:
        printFirst()
        self.l2.release()

    def second(self, printSecond: 'Callable[[], None]') -> None:
        self.l2.acquire()
        printSecond()
        self.l3.release()

    def third(self, printThird: 'Callable[[], None]') -> None:
        self.l3.acquire()
        printThird()

Complexity

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