欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

LeetCode 1115 交叉打印FooBar 附java代码

程序员文章站 2024-02-28 13:16:28
...

题目要求: 输入N,有两个线程,一个打印foo,一个打印bar 然后输出N个foobar。

LeetCode 1115 交叉打印FooBar 附java代码

 

代码如下:

class FooBar {
    private int n;

    private AtomicInteger value = new AtomicInteger(0);

    public FooBar(int n) {
        this.n = n;
    }

    public void foo(Runnable printFoo) throws InterruptedException {
        
        for (int i = 0; i < n; ) {
            
         synchronized (value) {
                    if (value.get() %2 ==0) {
                        // printFoo.run() outputs "foo". Do not change or remove this line.
                        printFoo.run();
                        i++;
                        value.getAndIncrement();
                        value.notify();
                    } else {
                        value.wait();
                    }
                }
        }
    }

    public void bar(Runnable printBar) throws InterruptedException {
        
        for (int i = 0; i < n; ) {
            
           synchronized (value) {
                    // printBar.run() outputs "bar". Do not change or remove this line.
                    if (value.get() %2 !=0) {
                        printBar.run();
                        i++;
                        value.getAndIncrement();
                        value.notify();
                    }else {
                        value.wait();
                    }
                }
        }
    }
}

第二种 用semaphore信号量

信号量就是限制一个方法中同时进行线程的个数

public class Problem1115 {

    private int n;

    private static Semaphore semaphore1 = new Semaphore(1);
    private static Semaphore semaphore2 = new Semaphore(0);


    public Problem1115(int n) {
        this.n = n;
    }

    public void foo(Runnable printFoo) throws InterruptedException {
        semaphore1.acquire();
        // printFoo.run() outputs "foo". Do not change or remove this line.
        printFoo.run();
        semaphore2.release();
    }

    public void bar(Runnable printBar) throws InterruptedException {
        // printBar.run() outputs "bar". Do not change or remove this line.
        semaphore2.acquire();
        printBar.run();
        semaphore1.release();
    }
}