# 2390. Removing Stars From a String

## Description

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.


Constraints:

• 1 <= s.length <= 105
• s consists of lowercase English letters and stars *.
• The operation above can be performed on s.

## Solutions

• class Solution {
public String removeStars(String s) {
StringBuilder ans = new StringBuilder();
for (int i = 0; i < s.length(); ++i) {
if (s.charAt(i) == '*') {
ans.deleteCharAt(ans.length() - 1);
} else {
ans.append(s.charAt(i));
}
}
return ans.toString();
}
}

• class Solution {
public:
string removeStars(string s) {
string ans;
for (char c : s) {
if (c == '*') {
ans.pop_back();
} else {
ans.push_back(c);
}
}
return ans;
}
};

• class Solution:
def removeStars(self, s: str) -> str:
ans = []
for c in s:
if c == '*':
ans.pop()
else:
ans.append(c)
return ''.join(ans)


• func removeStars(s string) string {
ans := []rune{}
for _, c := range s {
if c == '*' {
ans = ans[:len(ans)-1]
} else {
ans = append(ans, c)
}
}
return string(ans)
}

• function removeStars(s: string): string {
const ans: string[] = [];
for (const c of s) {
if (c === '*') {
ans.pop();
} else {
ans.push(c);
}
}
return ans.join('');
}


• class Solution {
/**
* @param String $s * @return String */ function removeStars($s) {
$rs = []; for ($i = 0; $i < strlen($s); $i++) { if ($s[$i] == '*') { array_pop($rs);
} else {
array_push($rs,$s[$i]); } } return join($rs);
}
}


• impl Solution {
pub fn remove_stars(s: String) -> String {
let mut ans = String::new();
for &c in s.as_bytes().iter() {
if c == b'*' {
ans.pop();
} else {
ans.push(char::from(c));
}
}
ans
}
}