题解 | #下一个更大的数(三)#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param n int整型 
     * @return int整型
     */
    public int nextGreaterElement(int n) {
        // write code here
        String str = n + "";
        char[] chrs = str.toCharArray();
        for (int currentIndex = chrs.length - 1; currentIndex > 0; currentIndex--) {
            if (chrs[currentIndex] > chrs[currentIndex - 1]) {
                char previousValue = chrs[currentIndex - 1];
                int swapIndex = currentIndex;
                for (int tmpIndex = currentIndex + 1; tmpIndex < chrs.length; tmpIndex++) {
                    if (chrs[tmpIndex] > previousValue && chrs[tmpIndex] < chrs[swapIndex]) {
                        swapIndex = tmpIndex;
                    }
                }
                chrs[currentIndex - 1] = chrs[swapIndex];
                chrs[swapIndex] = previousValue;
                Arrays.sort(chrs, currentIndex, chrs.length);
                break;
            }
        }
        StringBuffer sb = new StringBuffer("");
        for (char chr : chrs) {
            sb.append(chr);
        }
        return Integer.valueOf(new String(sb)) == n ? -1 : Integer.valueOf(new String(sb));
    }
}