LeetCode 179. Largest Number（最大数）

原题网址：https://leetcode.com/problems/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.
方法：将数字按照字符串进行比较，当两个数字为包含关系的时候（例如数字80和806，则将它们连接起来比较，80806和80680，看谁大，谁就应该排在前面）。

public class Solution {
public String largestNumber(int[] nums) {
String[] strs = new String[nums.length];
for(int i=0; i<nums.length; i++) strs[i] = Integer.toString(nums[i]);
Arrays.sort(strs, new Comparator<String>() {
@Override
public int compare(String s1, String s2) {
if (s1.length() == s2.length()) return s2.compareTo(s1);
return (s2+s1).compareTo(s1+s2);
}
});
if ("0".equals(strs[0])) return "0";
StringBuilder sb = new StringBuilder();
for(int i=0; i<strs.length; i++) {
sb.append(strs[i]);
}
return sb.toString();
}
}