556.Next Greater Element III

1-找逆序，排序

https://leetcode.com/problems/next-greater-element-iii/discuss/101824/

class Solution {
    public int nextGreaterElement(int n) {
        char[] number = (n + "").toCharArray();
        int i;
        for(i = number.length - 1; i > 0; i--){
            if(number[i - 1] < number[i])
                break;
        }
        //if the number is the largest
        if(i == 0)
            return  -1;

        int swapedVal = number[i - 1];
        int smallestValInRight = number[i];
        int smallestValPosInRight = i;
        for(int j = i + 1;  j < number.length; j++){
            if(number[j] > swapedVal && number[j] < smallestValInRight){
                smallestValInRight = number[j];
                smallestValPosInRight = j;
            }
        }
        char tmp = number[i - 1];
        number[i - 1] = number[smallestValPosInRight];
        number[smallestValPosInRight] = tmp;

        Arrays.sort(number, i, number.length);
        long val = Long.parseLong(new String(number));

        return (val <= Integer.MAX_VALUE) ? (int) val: -1;
    }
}