Java basics interview question 2

1. Use Java to implement two threads to print numbers and letters alternately. The printed results are as follows: 1 2 A 3 4 B ...... Y 51 52 Z

public class TestThread {    public static TestThread mHandler=new TestThread();    public static TestThread getHander(){        return mHandler;    }    public TestThread() {        // TODO Auto-generated constructor stub    }    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        TestThread t = new TestThread();        ThreadA threadA = t.new ThreadA();        ThreadB threadB = t.new ThreadB();        threadA.start();        threadB.start();    }        class ThreadA extends Thread{        private int num = 1;        @Override        public void run() {            // TODO Auto-generated method stub            super.run();            while(num<53){                synchronized(TestThread.this){  //synchronized(TestThread.getHander()){                    System.out.print(num+" "+(num+1)+" ");                    num+=2;                    TestThread.this.notify();                    if (num < 52){                        try {                            TestThread.this.wait();                        } catch (InterruptedException e) {                            // TODO Auto-generated catch block                            e.printStackTrace();                        }                    }                }            }        }    }        class ThreadB extends Thread{        private char ch = 'A';        @Override        public void run() {            // TODO Auto-generated method stub            super.run();            while(ch<='Z'){                synchronized(TestThread.this){  //synchronized(TestThread.getHander()){                    System.out.print(ch+" ");                    ch++;                    TestThread.this.notify();                    try {                        TestThread.this.wait();                    } catch (InterruptedException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }            }        }    }}

2. Place 100 to one hundred random natural numbers into array. Java is used to obtain the largest number of duplicates and print them out.

        Random ran = new Random();        int [] a=new int[100];        int [] b=new int[100];        for(int i=0;i<100;i++){            a[i]=Math.abs(ran.nextInt()%100);            System.out.print(a[i]+",");        }        System.out.println("----");        for(int i=0;i<100;i++){            b[a[i]]++;        }        for(int i=0;i<100;i++){            System.out.print(b[i]+",");        }        System.out.println("----");        int k=b[0],max=0;        for(int i=0;i<100;i++){            if(b[i]>=k){                k=b[i];                max=i;                System.out.println(max+"----"+k);            }        }        System.out.println(max+"----"+k);