public static float levenshtein(string str1, string str2)
  {
   //計(jì)算兩個(gè)字符串的長(zhǎng)度。 
   int len1 = str1.Length;
   int len2 = str2.Length;
   //建立上面說(shuō)的數(shù)組，比字符長(zhǎng)度大一個(gè)空間 
   int[,] dif = new int[len1 + 1, len2 + 1];
   //賦初值，步驟B。 
   for (int a = 0; a <= len1; a++)
   {
    dif[a, 0] = a;
   }
   for (int a = 0; a <= len2; a++)
   {
    dif[0, a] = a;
   }
   //計(jì)算兩個(gè)字符是否一樣，計(jì)算左上的值 
   int temp;
   for (int i = 1; i <= len1; i++)
   {
    for (int j = 1; j <= len2; j++)
    {
     if (str1[i - 1] == str2[j - 1])
     {
      temp = 0;
     }
     else
     {
      temp = 1;
     }
     //取三個(gè)值中最小的 
     dif[i, j] = Math.Min(Math.Min(dif[i - 1, j - 1] + temp, dif[i, j - 1] + 1), dif[i - 1, j] + 1);
    }
   }
   Console.WriteLine("字符串\"" + str1 + "\"與\"" + str2 + "\"的比較");

   //取數(shù)組右下角的值，同樣不同位置代表不同字符串的比較 
   Console.WriteLine("差異步驟：" + dif[len1, len2]);
   //計(jì)算相似度 
   float similarity = 1 - (float)dif[len1, len2] / Math.Max(str1.Length, str2.Length);
   Console.WriteLine("相似度：" + similarity);
   return similarity;
  }