[알고리즘문제풀기] 글자 지우기

문제

내가 작성한 정답

boolean[] - true

class Solution {
    public String solution(String my_string, int[] indices) {
        StringBuilder answer = new StringBuilder();
        boolean[] del = new boolean[my_string.length()];
        for(int i : indices){
            del[i] = true;
        }
        for(int i=0; i<my_string.length(); i++){
            if(!del[i]) answer.append(my_string.charAt(i));
        }
        return answer.toString();
    }
}

boolean[] - false

import java.util.Arrays;

class Solution {
    public String solution(String my_string, int[] indices) {
        StringBuilder answer = new StringBuilder();
        boolean[] save = new boolean[my_string.length()];
        Arrays.fill(save,true);
        for(int i : indices){
            save[i] = false;
        }
        for(int i=0; i<my_string.length(); i++){
            if(save[i]) answer.append(my_string.charAt(i));
        }
        return answer.toString();
    }
}

다른 사람들의 정답

String[]

class Solution {

    public String solution(String my_string, int[] indices) {
        String answer = "";
        String[] tmp = my_string.split("");

        for (int i = 0; i < indices.length; i++) {
            tmp[indices[i]] = "";
        }
        
        // 1. String.join
        // return String.join("",answer);
        
        // 2. for
        for (String x : tmp) {
            answer += x;
        }
        return answer;
    }
}

setCharAt - StringBuilder

class Solution {
    public String solution(String my_string, int[] indices) {
        StringBuilder sb = new StringBuilder(my_string);
        for (int i : indices) {
            sb.setCharAt(i, ' ');
        }
        return sb.toString().replace(" ", "");
    }
}