使用Stringbuilder拼接
class Solution {
public String removeDuplicates(String s) {
Stack<Character> nonDuplicates = new Stack<>();
for(int i = 0;i < s.length();i++){
if( !nonDuplicates.isEmpty() && s.charAt(i) == nonDuplicates.peek()){
nonDuplicates.pop();
continue;
}
nonDuplicates.push(s.charAt(i));
}
// 直接遍历(顺序为栈顶到栈底)
StringBuilder sb = new StringBuilder();
for (Character ch : nonDuplicates) {
sb.append(ch);
}
String result = sb.toString();
return result;
}
}