2390. Removing Stars From a String

Removing Stars From a String - LeetCode

문자열 s가 주어지며, 이 문자열에는 별표(*)가 포함되어 있습니다.
한 번의 연산에서 다음을 수행할 수 있습니다:
s에서 별표를 선택합니다.
해당 별표의 가장 가까운 왼쪽에 있는 비 별표 문자를 제거하고, 별표 자체도 제거합니다.
모든 별표가 제거된 후의 문자열을 반환하세요.

 

 

You are given a string s, which contains stars *.

In one operation, you can:

• Choose a star in s.
• Remove the closest non-star character to its left, as well as remove the star itself.

Return the string after all stars have been removed.

Note:

• The input will be generated such that the operation is always possible.
• It can be shown that the resulting string will always be unique.

 

Example 1:

Input: s = "leet**cod*e"
Output: "lecoe"
Explanation: Performing the removals from left to right:
- The closest character to the 1st star is 't' in "leet**cod*e". s becomes "lee*cod*e".
- The closest character to the 2nd star is 'e' in "lee*cod*e". s becomes "lecod*e".
- The closest character to the 3rd star is 'd' in "lecod*e". s becomes "lecoe".
There are no more stars, so we return "lecoe".

Example 2:

Input: s = "erase*****"
Output: ""
Explanation: The entire string is removed, so we return an empty string.

 

풀이과정 설명:

문자열을 순회하면서 별표를 찾습니다.
각 별표마다 가장 가까운 왼쪽에 있는 비 별표 문자를 제거합니다.
위의 과정을 반복하여 모든 별표를 제거하고 최종 문자열을 반환합니다.

 

 

class Solution {
    public String removeStars(String s) {
        Stack<String> stk = new Stack<>();

        for(String _s: s.split("")){
            if(_s.equals("*")){
                stk.pop();
            }else{
                stk.add(_s);
            }
        }

        String retStr = "";
        for(String _s: stk){
            retStr += _s;
        }
        return retStr;
    }
}