【真题编程】2017猪八戒

想的方法太笨了，开始想的是一位一位的比较

答案重写Collections.sort的compare方法很好，值得多看学习

import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.List; import java.util.Scanner;  public class Main {  	public static void main(String[] args) { 		Scanner in = new Scanner(System.in); 		while (in.hasNext()) { 			int n = in.nextInt(); 			List<Integer> list = new ArrayList<>(); 			for (int i = 0; i < n; i++) { 				list.add(in.nextInt()); 			}  			Collections.sort(list, new Comparator<Integer>() {  				@Override 				public int compare(Integer o1, Integer o2) { 					// TODO Auto-generated method stub 					String s1 = String.valueOf(o1); 					String s2 = String.valueOf(o2); 					//降序 					return (s2 + s1).compareTo(s1 + s2); 					//升序 				    //return (s1 + s2).compareTo(s2 + s1); 				}  			}); 			for (int i = 0; i < list.size(); i++) { 				System.out.print(list.get(i)); 			} 			System.out.println();  		} 	}  } 

文章来源: 【真题编程】2017猪八戒