Leetcode #1114: Print in Order
In this guide, we solve Leetcode #1114 Print in Order in Python and focus on the core idea that makes the solution efficient.
You will see the intuition, the step-by-step method, and a clean Python implementation you can use in interviews.
Problem Statement
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().
Quick Facts
- Difficulty: Easy
- Premium: No
- Tags: Concurrency
Intuition
The constraints allow a direct scan that keeps only the essential state.
By translating the requirements into a clean loop, the logic stays easy to reason about.
Approach
Iterate through the data once, updating the state needed to compute the answer.
Return the final state after the traversal is complete.
Steps:
- Parse the input.
- Iterate and update state.
- Return the computed answer.
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
The time complexity is , and the space complexity is . The space complexity is .
Edge Cases and Pitfalls
Watch for boundary values, empty inputs, and duplicate values where applicable. If the problem involves ordering or constraints, confirm the invariant is preserved at every step.
Summary
This Python solution focuses on the essential structure of the problem and keeps the implementation interview-friendly while meeting the constraints.