*[Lintcode]Largest Number 最大数

Given a list of non negative integers, arrange them such that they form the largest number.

Example

Given [1, 20, 23, 4, 8], the largest formed number is 8423201.

如果不想重写排序算法的话，使用Arrays.sort需要注意，必须将int数组改为对象类型，并且重写comparato

public class Solution {
    /**
     *@param num: A list of non negative integers
     *@return: A string
     */
    public String largestNumber(int[] num) {
        if(num.length == 0) return "";

        String[] strList = new String[num.length];
        
        for(int i = 0; i < num.length; i++) strList[i] = "" + num[i];
        
        Arrays.sort(strList, new comparatorI());

        int NonZero = 0;
        while(NonZero < strList.length && "0".equals(strList[NonZero]))
            NonZero++;

        StringBuilder sb = new StringBuilder();
        for(int i = NonZero; i < strList.length; i++){
            sb.append(strList[i]);
        }
        return sb.length() == 0 ? "0" : sb.toString();
    }
    
    class comparatorI implements Comparator<String> {
        public int compare(String s1, String s2) {
            return (s2 + s1).compareTo(s1 + s2);  
        }
    }
}

r。