leetcode720

    public class Solution
    {
        public string LongestWord(string[] words)
        {
            var maxlist = new List<string>();

            var dic = new Dictionary<string, string>();
            Queue<string> Q = new Queue<string>();
            var maxstr = "";

            foreach (var word in words)
            {
                var temp = word;
                if (!dic.ContainsKey(temp))
                {
                    dic.Add(temp, temp.Substring(0, temp.Length - 1));
                }
            }
            var list = dic.OrderByDescending(x => x.Key.Length).ToList();

            foreach (var l in list)
            {
                var cur = l.Key;
                if (cur.Length < maxstr.Length)
                {
                    continue;
                }

                Q.Enqueue(cur);
                var len = cur.Length;
                while (Q.Any())
                {
                    len--;
                    var temp = Q.Dequeue();
                    var subtemp = temp.Substring(0, temp.Length - 1);
                    if (dic.ContainsKey(subtemp))
                    {
                        Q.Enqueue(subtemp);
                    }
                }

                if (len == 0)
                {
                    maxlist.Add(cur);
                    maxstr = cur;
                }
            }

            var result = maxlist.OrderBy(x => x).ToList().FirstOrDefault();
            return result;
        }
    }