根据下面代码给出基于C#语言的判别是否为LR0文法的private void button2_Clickobject sender EventArgs e函数的完整代码可以适当增添变量定义namespace byyljxfzxt public partial class Form5 Form public Form5 Initia

private void button2_Click(object sender, EventArgs e) { string text = richTextBox1.Text; production = new Dictionary<string, List>(); string[] pro = text.Split('\n'); foreach (string s in pro) { if (s == "") continue;

    Regex.Replace(s, " ", "");
    string[] ga = Regex.Split(s, "->");
    if (ga.Length != 2) return;
    if (ga[0].Length == 0 || ga[1].Length == 0)
        return;
    if (ga[0].Length != 1 || !char.IsUpper(ga[0][0])) return;

    string[] ga2 = Regex.Split(ga[1], "\\|");
    if (!production.ContainsKey(ga[0]))
        production.Add(ga[0], new List<string>());
    foreach (string s1 in ga2)
        production[ga[0]].Add(s1);
}

// 判断是否为LR(0)文法
bool isLR0 = true;
foreach (var item in production)
{
    string left = item.Key;
    List<string> rightList = item.Value;
    foreach (string right in rightList)
    {
        if (right.Length == 1 && char.IsUpper(right[0])) // 形如A->B
        {
            if (!production.ContainsKey(right))
            {
                isLR0 = false;
                break;
            }
        }
        else if (right.Length > 1) // 形如A->aB或A->a
        {
            for (int i = 0; i < right.Length - 1; i++)
            {
                if (char.IsUpper(right[i]) && !char.IsUpper(right[i + 1])) // 形如A->aB
                {
                    string beta = right.Substring(i + 1);
                    foreach (string s in rightList)
                    {
                        if (s.Length == beta.Length && s.StartsWith(beta))
                        {
                            isLR0 = false;
                            break;
                        }
                    }
                }
            }
        }
        if (!isLR0) break;
    }
    if (!isLR0) break;
}
if (isLR0)
    MessageBox.Show("该文法是LR(0)文法");
else
    MessageBox.Show("该文法不是LR(0)文法");