Package g1101_1200.s1114_print_in_order

Class Foo

  • All Implemented Interfaces:
    
public final class Foo

    1114 - Print in Order\.

    Easy

    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(). Design a mechanism and modify the program to ensure that second() is executed after first(), and third() is executed after second().

    Note:

    We do not know how the threads will be scheduled in the operating system, even though the numbers in the input seem to imply the ordering. The input format you see is mainly to ensure our tests' comprehensiveness.

    Example 1:

    Input: nums = 1,2,3

    Output: "firstsecondthird"

    Explanation: There are three threads being fired asynchronously. The input 1,2,3 means thread A calls first(), thread B calls second(), and thread C calls third(). "firstsecondthird" is the correct output.

    Example 2:

    Input: nums = 1,3,2

    Output: "firstsecondthird"

    Explanation: The input 1,3,2 means thread A calls first(), thread B calls third(), and thread C calls second(). "firstsecondthird" is the correct output.

    Constraints:

    • nums is a permutation of [1, 2, 3].

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Foo()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Unit first(Runnable printFirst)
      final Unit second(Runnable printSecond)
      final Unit third(Runnable printThird)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait