2390. Removing Stars From a String ¶ Time: $O(n)$ Space: $O(n)$ C++JavaPython 1 2 3 4 5 6 7 8 9 10 11 12class Solution { public: string removeStars(string s) { string ans; for (const char c : s) if (c == '*') ans.pop_back(); else ans.push_back(c); return ans; } }; 1 2 3 4 5 6 7 8 9 10 11class Solution { public String removeStars(String s) { StringBuilder sb = new StringBuilder(); for (final char c : s.toCharArray()) if (c == '*') sb.deleteCharAt(sb.length() - 1); else sb.append(c); return sb.toString(); } } 1 2 3 4 5 6 7 8 9class Solution: def removeStars(self, s: str) -> str: ans = [] for c in s: if c == '*': ans.pop() else: ans.append(c) return ''.join(ans)