问题:用C# string []str = {"AA","QA","4A","4B" ,"QC","5C","4C","AD","5D"};
找出该数组元素中后一个字母出现次数唯一的一个,怎么写?
在此帖中看到一个回帖：
string[] result = str.GroupBy(s => s[s.Length - 1]).Where(g => g.Count() == 1).Select(g => str.First(s => s[s.Length-1] == g.Key)).ToArray();
直接取得结果
再度精简：string[] result = str.Where(s => str.Count(t => t[t.Length - 1] == s[s.Length - 1]) == 1).ToArray();