C#实现字符串相似度比较[Levenshtein Distance算法].

字符串相似度算法使用 Levenshtein Distance算法(中文翻译：编辑距离算法) 这算法是由俄国科学家Levenshtein提出的.

下面使用C#实现

public class LevenshteinDistance

{

private static LevenshteinDistance _instance=null;

public static LevenshteinDistance Instance

{

get

{

if (_instance == null)

{

return new LevenshteinDistance();

}

return _instance;

}

}

/// <summary>

/// 取最小的一位数

/// </summary>

/// <param name="first"></param>

/// <param name="second"></param>

/// <param name="third"></param>

/// <returns></returns>

public int LowerOfThree(int first, int second, int third)

{

int min = first;

if (second < min)

min = second;

if (third < min)

min = third;

return min;

}

public int Levenshtein_Distance(string str1, string str2)

{

int[,] Matrix;

int n=str1.Length;

int m=str2.Length;

int temp = 0;

char ch1;

char ch2;

int i = 0;

int j = 0;

if (n ==0)

{

return m;

}

if (m == 0)

{

return n;

}

Matrix=new int[n+1,m+1];

for (i = 0; i <= n; i++)

{

//初始化第一列

Matrix[i,0] = i;

}

for (j = 0; j <= m; j++)

{

//初始化第一行

Matrix[0, j] = j;

}

for (i = 1; i <= n; i++)

{

ch1 = str1[i-1];

for (j = 1; j <= m; j++)

{

ch2 = str2[j-1];

if (ch1.Equals(ch2))

{

temp = 0;

}

else

{

temp = 1;

}

Matrix[i,j] = LowerOfThree(Matrix[i - 1,j] + 1, Matrix[i,j - 1] + 1, Matrix[i - 1,j - 1] + temp);

}

}

for (i = 0; i <= n; i++)

{

for (j = 0; j <= m; j++)

{

Console.Write(" {0} ", Matrix[i, j]);

}

Console.WriteLine("");

}

return Matrix[n, m];

}

/// <summary>

/// 计算字符串相似度

/// </summary>

/// <param name="str1"></param>

/// <param name="str2"></param>

/// <returns></returns>

public decimal LevenshteinDistancePercent(string str1,string str2)

{

int maxLenth = str1.Length > str2.Length ? str1.Length : str2.Length;

int val = Levenshtein_Distance(str1, str2);

return 1 - (decimal)val / maxLenth;

}

}

class Program

{

static void Main(string[] args)

{

string str1 = "你好蒂蒂";

string str2="你好蒂芬";

Console.WriteLine("字符串1 {0}", str1);

Console.WriteLine("字符串2 {0}", str2);

Console.WriteLine("相似度 {0} %", LevenshteinDistance.Instance.LevenshteinDistancePercent(str1, str2)*100);

Console.ReadLine();

}

}