Leetcode9月1号打卡

1.leetcode1233题 删除子文件夹

很巧妙的题，字符串处理！加到hashmap里面，然后依次去判断，分割里面的''去判断

class Solution {
    public List<String> removeSubfolders(String[] folder) {
                Set<String> set = new HashSet<>();
        List<String> res = new ArrayList<>();

        for (String str : folder){
            set.add(str);
        }
        for (String str : folder){
            boolean isValid = true;
            for (int i = str.length() - 1;i > 1;i--){
                if (str.charAt(i) == '/'){
                    String temp = str.substring(0,i);
                    if (set.contains(temp)){
                        isValid = false;
                    }
                }
            }
            if (isValid){
                res.add(str);
            }
        }
        return res;
    }
}