?? guiyue.txt
字號:
using System;
using System.Collections.Generic;
using System.Text;
namespace 編譯實驗3
{
class Program
{
static void Main(string[] args)
{
string[] expression ={ "E->E+T|T", "T->T*F|F", "F->(E)|i" };
bool[,] FirstVT = new bool[3, 5];
bool[,] LastVT = new bool[3, 5];
Stack<string> stack = new Stack<string>();
string[] noendArry ={"E","T","F"};
string[] endArry={ "+", "*", "(", ")", "i" ,"#"};
List<string> end = new List<string>(endArry);
List<string> noend = new List<string>(noendArry);
char[,] table = new char[6, 6];
//求firstvt的集合
for (int i = 0; i < FirstVT .GetLength (0); i++)
{
for (int j = 0; j < FirstVT .GetLength (1); j++)
{
FirstVT[i, j] = false;
}
}
for (int i = 0; i < expression .Length; i++)
{
//確定產生式的第一個字母是否為終結符
int index=end.IndexOf(expression[i][3].ToString ());
if (index!=-1&& FirstVT[i, index] ==false)
{
stack.Push( noend[i]+expression[i][3]);
FirstVT[i, index] = true;
}
//確定產生式第一個字母為非終結符，第二個字母為終結符
int index1=noend.IndexOf(expression[i][3].ToString ());
int index2=end.IndexOf(expression[i][4].ToString ());
if (index1 != -1 && index2 != -1 && FirstVT[i, index2] == false)
{
stack.Push(noend[i] + expression[i][4]);
FirstVT[i, index2] = true;
}
//確定產生式的第二個表達式的第一個字母是否為終結符
int index3 = end.IndexOf(expression[i][7].ToString ());
if (index3 != -1 && FirstVT[i, index3] == false)
{
stack.Push(noend[i] + expression[i][7]);
FirstVT[i, index3] = true;
}
}
while (stack.Count != 0)
{
string element = stack.Pop();
for (int i = 0; i < expression .Length; i++)
{
if (expression[i][3] == element[0]&&FirstVT[i,end.IndexOf (element[1].ToString ())]==false)
{
stack.Push(noend[i] + element[1]);
FirstVT[i, end.IndexOf(element[1].ToString())] = true;
}
if (expression[i][7] == element[0] && FirstVT[i, end.IndexOf(element[1].ToString())] == false)
{
stack.Push(noend[i] + element[1]);
FirstVT[i, end.IndexOf(element[1].ToString())] = true;
}
}
}
//打印FirstVT集合
Console.WriteLine("FirstVT集為：");
for (int i = 0; i < FirstVT .GetLength (0); i++)
{
for (int j = 0; j< FirstVT .GetLength (1); j++)
{
Console.Write(FirstVT[i,j]+" ");
}
Console.WriteLine();
}
//求Lastvt的集合
for (int i = 0; i < LastVT.GetLength(0); i++)
{
for (int j = 0; j <LastVT.GetLength(1); j++)
{
LastVT[i, j] = false;
}
}
for (int i = 0; i < expression.Length; i++)
{
//確定產生式的倒數第一個字母是否為終結符
int index = end.IndexOf(expression[i][4].ToString());
if (index != -1 && LastVT[i, index] == false)
{
stack.Push(noend[i] + expression[i][4]);
LastVT[i, index] = true;
}
//確定產生式的倒數第一個字母為非終結符，倒數第二個字母為終結符
int index1 = noend.IndexOf(expression[i][4].ToString());
int index2 = end.IndexOf(expression[i][5].ToString());
if (index1 != -1 && index2 != -1 && LastVT[i, index2] == false)
{
stack.Push(noend[i] + expression[i][5]);
LastVT[i, index2] = true;
}
//確定產生式的第二個表達式的倒數第一個字母是否為終結符
int index3 = end.IndexOf(expression[i][7].ToString());
if (index3 != -1 && LastVT[i, index3] == false)
{
stack.Push(noend[i] + expression[i][7]);
LastVT[i, index3] = true;
}
}
while (stack.Count != 0)
{
string element = stack.Pop();
for (int i = 0; i < expression.Length; i++)
{
if (expression[i][5] == element[0] && LastVT[i, end.IndexOf(element[1].ToString())] == false)
{
stack.Push(noend[i] + element[1]);
LastVT[i, end.IndexOf(element[1].ToString())] = true;
}
if (expression[i][7] == element[0] && LastVT[i, end.IndexOf(element[1].ToString())] == false)
{
stack.Push(noend[i] + element[1]);
LastVT[i, end.IndexOf(element[1].ToString())] = true;
}
}
}
Console.WriteLine();
//打印LastVT集合
Console.WriteLine("LastVT集為：");
for (int i = 0; i < LastVT.GetLength(0); i++)
{
for (int j = 0; j < LastVT.GetLength(1); j++)
{
Console.Write(LastVT[i, j] + " ");
}
Console.WriteLine();
}
//求算符優先表
for (int i = 0; i < expression .Length ; i++)
{
for (int j = 3 ; j < expression [i].Length -3; j++)
{
int index3;
int index = end.IndexOf(expression[i][j].ToString ());
int index4 = noend.IndexOf(expression[i][j].ToString ());
int index1 = end.IndexOf(expression[i][j + 1].ToString ());
int index2 = noend.IndexOf(expression[i][j + 1].ToString ());
if (index == -1 && index1 == -1)
{
table[index,index1] = '=';
}
if (j <= expression[i].Length - 4 &&(index3= end.IndexOf(expression[i][j + 2].ToString ()))!=-1&&index!=-1)
{
if (index2 != -1)
{
table[index,index3] = '=';
}
}
if (index != -1 && index2 != -1)
{
for (int k = 0; k < 5; k++)
{
if (FirstVT[index2,k] == true)
{
table[index,k] = '<';
}
}
}
if (index4 != -1 && index1 != -1)
{
for (int k = 0; k < 5; k++)
{
if (LastVT[index4, k] == true)
{
table[k, index1] = '>';
}
}
}
}
}
for (int i = 0; i <5; i++)
{
if (FirstVT[0, i] == true)
{
table[5,i] = '<';
}
if (LastVT[0, i] == true)
{
table[i, 5] = '>';
}
}
table[5, 5] = '=';
//打印算符優先表
Console.WriteLine();
Console.WriteLine("算符優先表為：");
Console.Write(" ");
for (int i = 0; i < end.Count; i++)
{
Console.Write(end[i]+" ");
}
Console.WriteLine();
for (int i = 0; i < table.GetLength(0); i++)
{
Console.Write(end[i]+" ");
for (int j = 0; j < table.GetLength (1); j++)
{
Console.Write(table[i,j]+" ");
}
Console.WriteLine();
}
Console.WriteLine("請輸入要規約的句子以#結尾：");
string sentence = Console.ReadLine();
int top = 1;
int h,next=0;
char a;
char[] s = new char[20];
s[0]=' ';
s[1] = '#';
Console.WriteLine(s[1]);
do
{
a = sentence[next];
h = top;
//bool yes1;
int index0=-1;
int index=end.IndexOf(s[top].ToString());
int index1=end.IndexOf(a.ToString());
bool yes=(table[index,index1]=='>');
//找到了可規約串
while(yes)
{
//尋找可規約串
//do
//{
// char q=s[h];
// int index2=end.IndexOf(s[h-1].ToString());
// if(index2!=-1)
// {
// h=h-1;
// }
// else
// {
// h=h-2;
// }
// int index11 = end.IndexOf(s[h].ToString());
// // if (index != -1 && index11 != -1)
// //{
// yes1 = (table[index11, index] == '<');
// // }
// // else
// // {
// // yes1 = (table[index0, index11] == '>');
// // }
//}
//while(!yes1);
// int j = h;
//用產生式進行規約
for (int i = 0; i < 3; i++)
{
bool guiyue=false;
h = top;
for (int m = 5; m >2; m--)
{
int index4=end.IndexOf(expression[i][m].ToString ());
int index5 = end.IndexOf(s[h].ToString());
if (index4 != -1 && index5 != -1 && end[index4] == s[h].ToString())
{
h--;
}
else
{
if (index4 == -1 && index5 == -1)
{
h--;
}
else break;
}
if(m==3)
{
s[h+1] = expression[i][0];
top = h+1;
guiyue = true;
for (int j = 1; j<=top; j++)
{
Console.Write(s[j]);
}
Console.WriteLine();
}
}
if (guiyue==true) break;
h = top;
int index6 = end.IndexOf(expression[i][7].ToString());
if (index6!= -1 && end[index6] == s[h].ToString())
{
s[h] = expression[i][0];
top = h;
guiyue = true;
for ( int j = 1; j <= top; j++)
{
Console.Write(s[j]);
}
Console.WriteLine();
}
if (guiyue==true) break;
}
// index = end.IndexOf(s[top].ToString());
index1 = end.IndexOf(a.ToString());
index0 = end.IndexOf(s[top - 1].ToString());
// if (index != -1 && index1 != -1)
// {
// yes = (table[index, index1] == '>');
// }
// else
// {
yes = (table[index0, index1] == '>');
// }
}
// 找到了可規約串
// bool yesless = (table[index, index1] == '<');
// bool yesequal = (table[index, index1] == '=');
// if (yesless || yesequal)
//{
top++;
s[top] = a;
for (int i = 1; i <= top; i++)
{
Console.Write(s[i]);
}
Console.WriteLine();
//}
//else
//{
// Console.WriteLine("句子錯誤");
// return;
//}
next++;
}
while (a != '#');
Console.ReadLine();
}
}
}
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