缘由https://ask.csdn.net/questions/7883972/54063981
csharp
` List<List<string>> yssj = new List<List<string>> { new List<string> { "C01", "C51", "C53" }, new List<string> { "C01", "C67", "C65" } };
var jsj = yssj.SelectMany(s => s).Distinct().ToList();
List<string> xsj = new List<string>();//c# 想一句话把 List<List<string>>的元素合并成List<string>
foreach (var item in yssj) xsj = xsj.Union(item).ToList();
var jsj1 = yssj.Aggregate(new List<string>(), (res, item) => res.Union(item).ToList());`