获取所有重复开始出现连续

Question

同样有什么办法来翻译下面的查询

select word 
from string1 
where Left(word, 1) in (
    select Left(word, 1) as firstInitial 
    from string1 
    group by Left(word , 1) 
    having count(*) > 1 
) 

到LINQ，所以当你在运行“虽然金正日一直踢我吃了我的唐恩都乐以极大的趣味“它产生类似于

(miss,Match,Match,Match,miss,miss,miss,Match,Match,miss,Match,Match) 

Answer 1

以下解决方案显示了一种可能的方法。要使用此功能，请务必将MoreLINQ NuGet package添加到您的项目中。

using System; 
using System.Linq; 
using MoreLinq; 

namespace Test 
{ 
    class Program 
    { 
     static void Main(string[] args) 
     { 
      var input = "While Kim kept kicking I ate my Dunkin donut with great gusto"; 

      var value = input.Split(' '); 

      var lagged = value.Lag(1, (current, previous) => new { current = current?.ToLowerInvariant(), previous = previous?.ToLowerInvariant() }); 
      var leaded = value.Lead(1, (current, next) => new { next = next?.ToLowerInvariant() }); 

      var results = lagged.Zip(leaded, (x, y) => x.current?.FirstOrDefault() == x.previous?.FirstOrDefault() || 
                 x.current?.FirstOrDefault() == y.next?.FirstOrDefault()); 

      Console.WriteLine(string.Join(",", results)); 
      Console.ReadLine(); 
     } 
    } 
} 

基本上代码拆分串分成多个字，然后着眼于每个单词（current）和之前（previous）字和之后（next）它。然后它比较current的第一个字母与previous和next的第一个字母。

如果你想返回1/0而不是true/false然后改变只是这行代码：

var results = lagged.Zip(leaded, (x, y) => (x.current?.FirstOrDefault() == x.previous?.FirstOrDefault() || 
              x.current?.FirstOrDefault() == y.next?.FirstOrDefault()) ? 1 : 0); 

Answer 2

对于这个问题的解决不会像几行简单的，但我可以尝试：

首先，最简单的但不是那么优雅for循环方法：

var words = string1.Split(' ').ToList(); 
string[] results = new string[words.Count]; //edited: can use .Count instead of .Count() 
for (int i = 0; i < words.Count; i++) 
{ 
    if (i == words.Count - 1) 
     results[i] = char.ToLower(words[i - 1][0]) == char.ToLower(words[i][0]) ? "Match" : "miss"; 
    else if (i == 0) 
     results[i] = char.ToLower(words[i + 1][0]) == char.ToLower(words[i][0]) ? "Match" : "miss"; 
    else 
    { 
     bool leftMatch = char.ToLower(words[i - 1][0]) == char.ToLower(words[i][0]); 
     bool rightMatch = char.ToLower(words[i + 1][0]) == char.ToLower(words[i][0]); 
     results[i] = (leftMatch || rightMatch) ? "Match" : "miss"; 
    } 
} 

这样做是通过每个元素，如果左边或右边的单词有相同的首字符，它是一个“匹配”，否则它是“小姐”。对于第一个和最后一个字，它只是需要检查一个邻居，而不是2

使用LINQ的Enumerable.Range Method (Int32, Int32)，还有?: Operator，这可以简化为几行：

var words = string1.Split(' ').ToList(); 
var results = Enumerable.Range(0, words.Count).Select(i => i == words.Count - 1 ? 
     char.ToLower(words[i - 1][0]) == char.ToLower(words[i][0]) ? "Match" : "miss" : 
     i == 0 ? 
     char.ToLower(words[i + 1][0]) == char.ToLower(words[i][0]) ? "Match" : "miss" : 
     (char.ToLower(words[i - 1][0]) == char.ToLower(words[i][0]) || char.ToLower(words[i + 1][0]) == char.ToLower(words[i][0])) ? "Match" : "miss").ToList(); 

的ToList()在最后是可选的，如果你愿意，你可以转换ToArray()。