c# - c#中字符串与百分比的模糊匹配

Question

<分区>

Answer 1

我宁愿建议比较字典，而不是字符串:

1. 如果句子中有相同的词怎么办，例如“狐狸跳过狗”
2. 标点符号:句号、逗号等
3. 大小写，例如，“Fox”、“fox”、“FOX”等等。

所以实现

public static Dictionary<String, int> WordsToCounts(String value) {
  if (String.IsNullOrEmpty(value))
    return new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);

  return value
    .Split(' ', '\r', '\n', '\t')
    .Select(item => item.Trim(',', '.', '?', '!', ':', ';', '"'))
    .Where(item => !String.IsNullOrEmpty(item))
    .GroupBy(item => item, StringComparer.OrdinalIgnoreCase)
    .ToDictionary(chunk => chunk.Key, 
                  chunk => chunk.Count(), 
                  StringComparer.OrdinalIgnoreCase);
}

public static Double DictionaryPercentage(
  IDictionary<String, int> left,
  IDictionary<String, int> right) {

  if (null == left)
    if (null == right)
      return 1.0;
    else
      return 0.0;
  else if (null == right)
    return 0.0;

  int all = left.Sum(pair => pair.Value);

  if (all <= 0)
    return 0.0;

  double found = 0.0;

  foreach (var pair in left) {
    int count;

    if (!right.TryGetValue(pair.Key, out count))
      count = 0;

    found += count < pair.Value ? count : pair.Value;
  }

  return found / all;
}

public static Double StringPercentage(String left, String right) {
  return DictionaryPercentage(WordsToCounts(left), WordsToCounts(right));
}

您提供的 sample 将是

  String original = "Quick Brown Fox Jumps over the lazy dog";

  String[] extracts = new String[] {
    "This is un-match string with above string.",
    "Quick Brown fox Jumps.",
    "brown fox jumps over the lazy.",
    "quick brown fox over the dog.",
    "fox jumps over the lazy dog.",
    "jumps over the.",
    "lazy dog.",
  };

  var data = extracts
    .Select(item => new {
      text = item,
      perCent = StringPercentage(original, item) * 100.0
    })
    //.Where(item => item.perCent >= 60.0) // uncomment this to apply threshold
    .Select(item => String.Format(CultureInfo.InvariantCulture, 
      "\"{0}\" \t {1:F2}%", 
      item.text, item.perCent));

  String report = String.Join(Environment.NewLine, data);

  Console.write(report);

报告是

  "This is un-match string with above string."   0.00%
  "Quick Brown fox Jumps."                      50.00%
  "brown fox jumps over the lazy."              75.00%
  "quick brown fox over the dog."               75.00%
  "fox jumps over the lazy dog."                75.00%
  "jumps over the."                             37.50%
  "lazy dog."                                   25.00%