C#实现的字符串相似度对比类

本类适用于比较2个字符的相似度，代码如下：

using system;
using system.collections.generic;
using system.text;

public class stringcompute
{
  #region 私有变量
  /// <summary>
  /// 字符串1
  /// </summary>
  private char[] _arrchar1;
  /// <summary>
  /// 字符串2
  /// </summary>
  private char[] _arrchar2;
  /// <summary>
  /// 统计结果
  /// </summary>
  private result _result;
  /// <summary>
  /// 开始时间
  /// </summary>
  private datetime _begintime;
  /// <summary>
  /// 结束时间
  /// </summary>
  private datetime _endtime;
  /// <summary>
  /// 计算次数
  /// </summary>
  private int _computetimes;
  /// <summary>
  /// 算法矩阵
  /// </summary>
  private int[,] _matrix;
  /// <summary>
  /// 矩阵列数
  /// </summary>
  private int _column;
  /// <summary>
  /// 矩阵行数
  /// </summary>
  private int _row;
  #endregion
  #region 属性
  public result computeresult
  {
    get { return _result; }
  }
  #endregion
  #region 构造函数
  public stringcompute(string str1, string str2)
  {
    this.stringcomputeinit(str1, str2);
  }
  public stringcompute()
  {
  }
  #endregion
  #region 算法实现
  /// <summary>
  /// 初始化算法基本信息
  /// </summary>
  /// <param name="str1">字符串1</param>
  /// <param name="str2">字符串2</param>
  private void stringcomputeinit(string str1, string str2)
  {
    _arrchar1 = str1.tochararray();
    _arrchar2 = str2.tochararray();
    _result = new result();
    _computetimes = 0;
    _row = _arrchar1.length + 1;
    _column = _arrchar2.length + 1;
    _matrix = new int[_row, _column];
  }
  /// <summary>
  /// 计算相似度
  /// </summary>
  public void compute()
  {
    //开始时间
    _begintime = datetime.now;
    //初始化矩阵的第一行和第一列
    this.initmatrix();
    int intcost = 0;
    for (int i = 1; i < _row; i++)
    {
      for (int j = 1; j < _column; j++)
      {
        if (_arrchar1[i - 1] == _arrchar2[j - 1])
        {
          intcost = 0;
        }
        else
        {
          intcost = 1;
        }
        //关键步骤，计算当前位置值为左边+1、上面+1、左上角+intcost中的最小值 
        //循环遍历到最后_matrix[_row - 1, _column - 1]即为两个字符串的距离
        _matrix[i, j] = this.minimum(_matrix[i - 1, j] + 1, _matrix[i, j - 1] + 1, _matrix[i - 1, j - 1] + intcost);
        _computetimes++;
      }
    }
    //结束时间
    _endtime = datetime.now;
    //相似率 移动次数小于最长的字符串长度的20%算同一题
    int intlength = _row > _column ? _row : _column;

    _result.rate = (1 - (decimal)_matrix[_row - 1, _column - 1] / intlength);
    _result.usetime = (_endtime - _begintime).tostring();
    _result.computetimes = _computetimes.tostring();
    _result.difference = _matrix[_row - 1, _column - 1];
  }


  /// <summary>
  /// 计算相似度（不记录比较时间）
  /// </summary>
  public void speedycompute()
  {
    //开始时间
    //_begintime = datetime.now;
    //初始化矩阵的第一行和第一列
    this.initmatrix();
    int intcost = 0;
    for (int i = 1; i < _row; i++)
    {
      for (int j = 1; j < _column; j++)
      {
        if (_arrchar1[i - 1] == _arrchar2[j - 1])
        {
          intcost = 0;
        }
        else
        {
          intcost = 1;
        }
        //关键步骤，计算当前位置值为左边+1、上面+1、左上角+intcost中的最小值 
        //循环遍历到最后_matrix[_row - 1, _column - 1]即为两个字符串的距离
        _matrix[i, j] = this.minimum(_matrix[i - 1, j] + 1, _matrix[i, j - 1] + 1, _matrix[i - 1, j - 1] + intcost);
        _computetimes++;
      }
    }
    //结束时间
    //_endtime = datetime.now;
    //相似率 移动次数小于最长的字符串长度的20%算同一题
    int intlength = _row > _column ? _row : _column;

    _result.rate = (1 - (decimal)_matrix[_row - 1, _column - 1] / intlength);
    // _result.usetime = (_endtime - _begintime).tostring();
    _result.computetimes = _computetimes.tostring();
    _result.difference = _matrix[_row - 1, _column - 1];
  }
  /// <summary>
  /// 计算相似度
  /// </summary>
  /// <param name="str1">字符串1</param>
  /// <param name="str2">字符串2</param>
  public void compute(string str1, string str2)
  {
    this.stringcomputeinit(str1, str2);
    this.compute();
  }

  /// <summary>
  /// 计算相似度
  /// </summary>
  /// <param name="str1">字符串1</param>
  /// <param name="str2">字符串2</param>
  public void speedycompute(string str1, string str2)
  {
    this.stringcomputeinit(str1, str2);
    this.speedycompute();
  }
  /// <summary>
  /// 初始化矩阵的第一行和第一列
  /// </summary>
  private void initmatrix()
  {
    for (int i = 0; i < _column; i++)
    {
      _matrix[0, i] = i;
    }
    for (int i = 0; i < _row; i++)
    {
      _matrix[i, 0] = i;
    }
  }
  /// <summary>
  /// 取三个数中的最小值
  /// </summary>
  /// <param name="first"></param>
  /// <param name="second"></param>
  /// <param name="third"></param>
  /// <returns></returns>
  private int minimum(int first, int second, int third)
  {
    int intmin = first;
    if (second < intmin)
    {
      intmin = second;
    }
    if (third < intmin)
    {
      intmin = third;
    }
    return intmin;
  }
  #endregion
}
/// <summary>
/// 计算结果
/// </summary>
public struct result
{
  /// <summary>
  /// 相似度
  /// </summary>
  public decimal rate;
  /// <summary>
  /// 对比次数
  /// </summary>
  public string computetimes;
  /// <summary>
  /// 使用时间
  /// </summary>
  public string usetime;
  /// <summary>
  /// 差异
  /// </summary>
  public int difference;
}

调用方法：

// 方式一
stringcompute stringcompute1 = new stringcompute();
stringcompute1.speedycompute("对比字符一", "对比字符二");  // 计算相似度， 不记录比较时间
decimal rate = stringcompute1.computeresult.rate;     // 相似度百分之几，完全匹配相似度为1

// 方式二
stringcompute stringcompute2 = new stringcompute();
stringcompute2.compute();                 // 计算相似度， 记录比较时间
string usetime = stringcompute2.computeresult.usetime;   // 对比使用时间