문제

풀이

public String solution(String s) {
    char[] arr = s.toLowerCase().toCharArray();

    return IntStream.range(0, arr.length)
            .mapToObj(i -> i != 0 && arr[i - 1] != ' ' ? arr[i] : Character.toUpperCase(arr[i]))
            .map(Object::toString)
            .collect(Collectors.joining());
}