- public class LevenshteinDistance
- {
- #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 LevenshteinDistance(string str1, string str2)
- {
- this.LevenshteinDistanceInit(str1,str2);
- }
- public LevenshteinDistance()
- {
- }
- #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 LevenshteinDistanceInit(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 - (double)_Matrix[_Row - 1, _Column - 1] / intLength).ToString().Substring(0, 6);
- if (_Result.Rate.Length > 6)
- {
- _Result.Rate = _Result.Rate.Substring(0, 6);
- }
- _Result.UseTime = (_EndTime - _BeginTime).ToString();
- _Result.ComputeTimes = _ComputeTimes.ToString() + " 距离为:" + _Matrix[_Row - 1, _Column - 1].ToString();
- }
- /// <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.LevenshteinDistanceInit(str1, str2);
- this.Compute();
- }
- /// <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 string Rate;
- /// <summary>
- /// 对比次数
- /// </summary>
- public string ComputeTimes;
- /// <summary>
- /// 使用时间
- /// </summary>
- public string UseTime;
- }
- //该片段来自于http://www.codesnippet.cn/detail/120820135094.html
来源: http://www.codesnippet.cn/detail/120820135094.html