Design an Ordered Stream

要求设计一个流, 问返回最大的连续长度的id.

class OrderedStream {
    int ptr = 1;
    Map<Integer, String> map;
    public OrderedStream(int n) {
         map = new HashMap<>();
    }
    
    public List<String> insert(int id, String value) {
        List<String> res = new ArrayList<>();
        map.put(id, value);
        while(map.containsKey(ptr)){
            ptr++;
        }
        for(int i = id; i < ptr; i++){
            res.add(map.get(i));
        }
        return res;
    }
}

/**
 * Your OrderedStream object will be instantiated and called as such:
 * OrderedStream obj = new OrderedStream(n);
 * List<String> param_1 = obj.insert(id,value);
 */