TreeSet的使用：获得一组数中的不同数（排序）

import java.io.BufferedInputStream;

import java.util.Iterator;

import java.util.Scanner;

import java.util.Set;

import java.util.TreeSet;



public class Main {

	public static void main(String[] args) {

		Scanner cin = new Scanner(new BufferedInputStream(System.in));

		Set<Number> numberSet = new TreeSet<Number>();

		int[] numberArrays = null;

		int nalength = -1;

		Number num = null;

		while (cin.hasNext()) {

			System.out.print("请输入数组的大小：");

			nalength = cin.nextInt();

			System.out.print("\n请输入数组中的元素以空格隔开：");

			numberArrays = new int[nalength];

			for (int i = 0; i < nalength; i++) {

				numberArrays[i] = cin.nextInt();

				num = new Number(numberArrays[i]);

				numberSet.add(num);

			}

			Iterator<Number> iter = numberSet.iterator();

			System.out.print("\n数组中的不同的元素，如下所示：\n");

			while (iter.hasNext()) {

				System.out.print(iter.next().number);

				if (iter.hasNext()) {

					System.out.print(" ");

				}

			}

			System.out.println();

		}

	}

}



class Number implements Comparable<Number> {

	int number;



	Number(int number) {

		this.number = number;

	}



	@Override

	public int compareTo(Number num) {

		int res = this.number - num.number;

		if (res > 0) {

			return 1;

		} else if (res < 0) {

			return -1;

		}

		return 0;

	}

}