LeetCode 179. 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.

解题思路：

该题目需要防止出现都是0的状态

java

class Solution {    public String largestNumber(int[] nums) {        if (nums == null || nums.length == 0) {            return "";        }        Integer[] arr = new Integer[nums.length];        for (int i = 0; i < nums.length; i++) {            arr[i] = new Integer(nums[i]);        }        Comparator<Integer> cmp = new Comparator<Integer>() {            public int compare(Integer a1, Integer a2) {                String str1 = a1 + "" + a2;                String str2 = a2 + "" + a1;                return -str1.compareTo(str2);            }        };        Arrays.sort(arr, cmp);        StringBuffer sb = new StringBuffer();        for (int val : arr) {            sb.append(val);        }        String str = sb.toString();        if (str.charAt(0) == '0' && str.charAt(str.length() - 1) == '0') {            return 0 + "";        } else {            return str;        }    }}