230522 큰 수 만들기

public String solution(String number, int k) {
    StringBuilder sb = new StringBuilder();
    int maxIndex = 0;

    for (int i = 0; i < number.length() - k; i++) {
        int maxDigit = 0;
        for (int j = maxIndex; j <= k + i; j++) {
            int digit = number.charAt(j) - '0';
            if (digit > maxDigit) {
                maxDigit = digit;
                maxIndex = j + 1;
            }
            if (maxDigit == 9)
                break;
        }
        sb.append(maxDigit);
    }

    return sb.toString();
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/42883