c# - 如何比较 2 个字符串数组并找到所有连续匹配项并保存索引？

Question

例如，如果我有以下 2 个数组:

string[] userSelect = new string[] {"the", "quick", "brown", "dog", "jumps", "over"};
string[] original = new string[] {"the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"};

我正在尝试将 userSelect 数组与原始数组进行比较，并根据索引获取所有连续的匹配项。 userSelect 数组将始终由原始数组中的字符串组成。所以输出将如下所示:

int[] match0 = new int[] {0, 1, 2}; // indices for "the quick brown"
int[] match2 = new int[] {4, 5}; // indices for "jumps over"
int[] match1 = new int[] {3}; // index for "dog"

userSelect 数组长度永远不会超过原始数组长度，但它可以更短并且单词可以按任意顺序排列。我该怎么做呢？

Answer 1

这是我想出来的

var matches = 
    (from l in userSelect.Select((s, i) => new { s, i })
     join r in original.Select((s, i) => new { s, i }) 
     on l.s equals r.s 
     group l by r.i - l.i into g
     from m in g.Select((l, j) => new { l.i, j = l.i - j, k = g.Key })
     group m by new { m.j, m.k } into h
     select h.Select(t => t.i).ToArray())
    .ToArray();

这将输出

matches[0] // { 0, 1, 2 } the quick brown
matches[1] // { 4, 5 } jumps over
matches[2] // { 0 } the 
matches[3] // { 3 } dog

使用输入 {"the", "quick", "brown", "the", "lazy", "dog"} 产生:

matches[0] // { 0, 1, 2 } the quick brown
matches[1] // { 0 } the 
matches[2] // { 3 } the
matches[3] // { 3, 4, 5 } the lazy dog

请注意，对 ToArray 的调用是可选的。如果您实际上不需要数组中的结果，您可以将其省略并节省一点处理时间。

要过滤掉与其他较大序列完全包含的任何序列，您可以运行此代码(注意修改后的查询中的 orderby):

var matches = 
    (from l in userSelect.Select((s, i) => new { s, i })
     join r in original.Select((s, i) => new { s, i }) 
     on l.s equals r.s 
     group l by r.i - l.i into g
     from m in g.Select((l, j) => new { l.i, j = l.i - j, k = g.Key })
     group m by new { m.j, m.k } into h
     orderby h.Count() descending
     select h.Select(t => t.i).ToArray());

int take = 0;
var filtered = matches.Where(m => !matches.Take(take++)
                                          .Any(n => m.All(i => n.Contains(i))))
    .ToArray();