Remove All Adjacent Duplicates In String

class Solution {
public:
    string removeDuplicates(string s) {
        string st;
        st.reserve(s.size());
        for (char c : s) {
            if (!st.empty() && st.back() == c) st.pop_back();
            else st.push_back(c);
        }
        return st;
    }
};

func removeDuplicates(s string) string {
    st := make([]byte, 0, len(s))
    for i := 0; i < len(s); i++ {
        c := s[i]
        if len(st) > 0 && st[len(st)-1] == c {
            st = st[:len(st)-1]
        } else {
            st = append(st, c)
        }
    }
    return string(st)
}

class Solution:
    def removeDuplicates(self, s: str) -> str:
        st: list[str] = []
        for c in s:
            if st and st[-1] == c:
                st.pop()
            else:
                st.append(c)
        return ''.join(st)

function removeDuplicates(s) {
    const st = [];
    for (const c of s) {
        if (st.length > 0 && st[st.length - 1] === c) st.pop();
        else st.push(c);
    }
    return st.join('');
}

class Solution {
    public String removeDuplicates(String s) {
        StringBuilder st = new StringBuilder();
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            int len = st.length();
            if (len > 0 && st.charAt(len - 1) == c) {
                st.deleteCharAt(len - 1);
            } else {
                st.append(c);
            }
        }
        return st.toString();
    }
}

function removeDuplicates(s: string): string {
    const st: string[] = [];
    for (const c of s) {
        if (st.length > 0 && st[st.length - 1] === c) st.pop();
        else st.push(c);
    }
    return st.join('');
}