刚看到几年前自己写的代码，突然感觉现在智力下降了

/// <summary>
/// 计算字符串中子串出现的次数
/// </summary>
/// <param name="str">字符串</param>
/// <param name="substring">子串</param>
/// <returns>出现的次数</returns>
public static int SubstringCount(string str, string substring)
{
if (!str.Contains(substring)) return 0;
string strReplaced = str.Replace(substring, "");
return (str.Length - strReplaced.Length) / substring.Length;
}
/// <summary>
/// 某个字符在这个位置之前出现过几次
/// </summary>
/// <param name="str">字符串</param>
/// <param name="s">某字符</param>
/// <param name="ec">位置</param>
/// <returns></returns>
public static int pCount(string str,string s,int ec)
{
return SubstringCount(str.Substring(0, ec), s);
}