[레벨 2] JadenCase 문자열 만들기

#include <string>
#include <vector>
using namespace std;
string solution(string s) {
    string answer = "";
    int len = s.size();
    if (s[0] >= 'a' && s[0] <= 'z')
        answer += toupper(s[0]);
    else
        answer += s[0];
    for (int i = 1; i < len; ++i)
    {
        if (s[i] == ' ')
        {
            answer += s[i];
            int j = i + 1;
            if (j == len)
                break;
            while (s[j] == ' ')
            {
                answer += s[j];
                ++j;
            }
            
            if (s[j] >= 'a' && s[j] <= 'z')
                answer += toupper(s[j]);
            else
                answer += s[j];
            i = j;
        }
        else
        {
            if (s[i] >= 'A' && s[i] <= 'Z')
                answer += tolower(s[i]);
            else
                answer += s[i];
        }
    }
    return answer;
}