class CComputeSim
{
    private int min(int one, int two, int three)
    {
        int min = one;

        if (two < min)
             min = two;
        if (three < min)
             min = three;

        return min;
    }

    public int lod(String str1, String str2)
    {
        int[,] d = null;    //矩阵
        int n = str1.Length;
        int m = str2.Length;
        int i;        //遍历str1的
        int j;       //遍历str2的
        char[] ch1 = str1.ToCharArray();    //str1的
        char[] ch2 = str2.ToCharArray();     //str2的
        int temp;      //记录相同字符,在某个矩阵位置值的增量,不是0就是1

        if (n == 0)     
             return m;
        if (m == 0)     
             return n;

        d = new int[n + 1, m + 1];
        if (n != m)
        {
            for (i = 0; i <= n; i++)    //初始化第一列
                d[i, 0] = i;
            for (j = 0; j <= m; j++)    //初始化第一行
                d[0, j] = j;
        }
        else
        {
            for (i = 0; i <= n; i++)    //初始化第一列
            {
                d[i, 0] = i;
                d[0, i] = i;
            }
        }
        for (i = 1; i <= n; i++)    //遍历str1
        {
            for (j = 1; j <= m; j++)
            {
                if (ch1[i - 1] == ch2[j - 1])
                    temp = 0;
                else
                    temp = 1;

                //左边+1,上边+1, 左上角+temp取最小
                d[i,j] = min(d[i-1,j] + 1, d[i,j-1] + 1, d[i-1,j-1] + temp);
            }
        }
        return d[n, m];
    }
    public double sim(String str1, String str2, bool caseSensitive)
    {
        if (caseSensitive == false)//是否区分大小写，false表示不区分大小写
        {
            str1 = str1.ToLower();
            str2 = str2.ToLower();
        }
        int ld = lod(str1, str2);
        return 1 - (double)ld / Math.Max(str1.Length, str2.Length);
    }
}