LeetCode Largest Number

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 }

 

posted @ 2015-01-14 23:54  birdhack  阅读(234)  评论(0)  编辑  收藏  举报