Hackerrank - Bigger is Greater

GetNextWord.java

// https://www.hackerrank.com/challenges/bigger-is-greater
// Given a word , rearrange the letters of  to construct another word  in such a way that  is lexicographically greater than . In case of multiple possible answers, find the lexicographically smallest one among them.

// Input Format
// The first line of input contains , the number of test cases. Each of the next  lines contains .

// Constraints
// will contain only lower-case English letters and its length will not exceed .
// Output Format

// For each testcase, output a string lexicographically bigger than  in a separate line. In case of multiple possible answers, print the lexicographically smallest one, and if no answer exists, print no answer.

// Sample Input

// 5
// ab
// bb
// hefg
// dhck
// dkhc
// Sample Output

// ba
// no answer
// hegf
// dhkc
// hcdk

public class GetNextWord {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        for (int i = 0; i < n; i++) {
            char[] array = scanner.next().toCharArray();
            List list = new ArrayList();
            for (char c : array) {
                list.add(c);
            }
            System.out.println(getNext(list));
        }
    }

    private static String getNext(List<Character> array) {
        List<Character> result;
        if (array.size() == 1) {
            return "no answer";
        } else if (array.size() == 2) {
            if (getAlphPos(array.get(0)) >= getAlphPos(array.get(1))) {
                return "no answer";
            } else {
                if (getAlphPos(array.get(0)) < getAlphPos(array.get(1))) {
                    swapItems(array, 0, 1);
                }
                result = array;
            }
        } else {
            int pos = -1;
            for (int i = array.size() - 1; i > 0; --i) {
                if (getAlphPos(array.get(i)) > getAlphPos(array.get(i - 1))) {
                    pos = i - 1;
                    break;
                }
            }
            if (pos == -1) {
                return "no answer";
            }

            result = new ArrayList<>(array.subList(0, pos));
            List<Character> sorted = new ArrayList<>(array.subList(pos, array.size()));
            Collections.sort(sorted);

            Character character = array.get(pos);
            for (int i = 0; i < sorted.size(); i++) {
                if (getAlphPos(character) < getAlphPos(sorted.get(i))) {
                    result.add(sorted.remove(i));
                    break;
                }

            }
            result.addAll(sorted);
        }
        StringBuilder builder = new StringBuilder();
        for (Character c : result) {
            builder.append(c);
        }
        return builder.toString();
    }

    private static void swapItems(List<Character> array, int first, int second) {
        char temp = array.get(second);
        array.set(second, array.get(first));
        array.set(first, temp);
    }


    private static int getAlphPos(char c) {
        int temp = (int) c;
        return temp - 96;
    }
}