一种排序

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Scanner;
import java.util.Set;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = Integer.parseInt(sc.nextLine());
		// 有n个测试数据
		while (n-- > 0) {
			// 接收有几个矩形
			int count = Integer.parseInt(sc.nextLine());// count=8
			Set<Rect> set = new HashSet<Rect>();
			for (int i = 0; i < count; i++) {
				String rectStr = sc.nextLine();// 1 2 1
				String[] rectS = rectStr.split(" ");
				// 计算出矩形的长和宽
				int length = Math.max(Integer.parseInt(rectS[1]),
						Integer.parseInt(rectS[2]));
				int width = Math.min(Integer.parseInt(rectS[1]),
						Integer.parseInt(rectS[2]));
				Rect rect = new Rect(Integer.parseInt(rectS[0]), length, width);
				set.add(rect);
			}
			List<Rect> list = new ArrayList<Rect>(set);
			Collections.sort(list, new MyComparator());
			for (Rect rect : list) {
				System.out.println(rect.id + " " + rect.length + " "
						+ rect.width);
			}
		}
	}
}

// 定义我自己的比较器
class MyComparator implements Comparator<Rect> {
	/**
	 * 两个矩形，若果矩形id不同，就按照矩形升序排列 如果矩形id同，就按照矩形的长升序排列 如果矩形id同，并且矩形的长同，就按照矩形的宽升序排序
	 */
	@Override
	public int compare(Rect o1, Rect o2) {
		if (o1.id != o2.id) {
			return o1.id - o2.id;
		} else if (o1.length != o2.length) {
			return o1.length - o2.length;
		} else {
			// 说明id和length也相同
			return o1.width - o2.width;
		}
	}
}
class Rect {
	int id;
	int length;// 矩形的长
	int width;// 矩形的宽
	public Rect(int id, int length, int width) {
		this.id = id;
		this.length = length;
		this.width = width;
	}
	// 这里重新equals方法和hashCode,用id和length和width来标识
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + id;
		result = prime * result + length;
		result = prime * result + width;
		return result;
	}
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Rect other = (Rect) obj;
		if (id != other.id)
			return false;
		if (length != other.length)
			return false;
		if (width != other.width)
			return false;
		return true;
	}
}

一种排序

原文：http://blog.csdn.net/x380481791/article/details/51346133