[알고리즘문제풀기] 문자열 계산하기

문제

내가 작성한 정답

class Solution {
    public int solution(String my_string) {
        String[] arr = my_string.split(" ");
        int answer = Integer.parseInt(arr[0]);
        for(int i=1; i<arr.length-1; i++){
            if(arr[i].equals("+")) answer+=Integer.parseInt(arr[i+1]);
            else if (arr[i].equals("-")) answer -= Integer.parseInt(arr[i+1]);
        }
        return answer;
    }
}

class Solution {
    public int solution(String my_string) {
        int answer = 0;
        for(String s: my_string.replaceAll("- ","-")
                .replaceAll("\\+ ","").split(" ")){
            answer += Integer.parseInt(s);
        }
        return answer;
    }
}

다른 사람들의 정답

import java.util.Arrays;

class Solution {
    public int solution(String myString) {
        return Arrays.stream(myString.replaceAll("- ", "-").replaceAll("[+] ", "").trim().split(" ")).mapToInt(Integer::parseInt).sum();
    }
}

class Solution {
    public int solution(String my_string) {
        int answer = 0;
        boolean sign = true;
        String[] sarr = my_string.split(" ");
        for(int i=0; i<sarr.length; i++){
            if(i%2==0){
                answer += sign? Integer.parseInt(sarr[i]):-Integer.parseInt(sarr[i]);
            }else{
                sign = sarr[i].equals("+");
            }
        }
        return answer;
    }
}