Given a list of non negative integers, arrange them such that they form the largest number.
For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330.
Note: The result may be very large, so you need to return a string instead of an integer.
Credits:
Special thanks to @ts for adding this problem and creating all test cases.
1 class StringComparator implements Comparator<String> { 2 3 @Override 4 public int compare(String a, String b) { 5 if (a.length() == b.length()) { 6 return b.compareTo(a); 7 } else { 8 String ab = a + b; 9 String ba = b + a; 10 return ba.compareTo(ab); 11 } 12 } 13 } 14 public class Solution { 15 public String largestNumber(int[] num) { 16 ArrayList<String> list = new ArrayList<String>(num.length); 17 for (int i = 0; i < num.length; i++) { 18 list.add(String.valueOf(num[i])); 19 } 20 Collections.sort(list,new StringComparator()); 21 String result = ""; 22 for (String s : list) { 23 result += s; 24 } 25 if(result.charAt(0)==‘0‘) return "0"; 26 return result; 27 } 28 }
原文：http://www.cnblogs.com/birdhack/p/4225190.html