[Level 2] 큰 수 만들기

class Solution {
    public String solution(String number, int k) {
        String answer = "";
        int len = number.length()-k;
        
        for(int i=0; i<number.length(); i++) {
            if(answer.length()==len) { break; }
            if(k==0) { return answer+number.substring(i, number.length()); }
            
            char c = number.charAt(i);
            boolean delete = true;
            
            for(int j=i+1; j<=i+k; j++) {
                if(c<number.charAt(j)) {
                    delete = false;
                    k--;
                    break;
                }
            }
            
            if(delete) { answer += String.valueOf(c); }
        }
        
        return answer;
    }
}