package?re.sa;

import?java.io.BufferedReader;
import?java.io.IOException;
import?java.io.InputStreamReader;

public?class?LL1SA?{
	/*
	?*?原始文法：
	?*?
	?*?E→E+T|E/T|T?
	?*?T→T-F|T*F|F?
	?*?F→（E）|i?
	?*/

	/*
	?*?消除左遞歸
	?*?
	?*?E→TM?
	?*?M→+TM|/TM|ε?
	?*?T→FN?
	?*?N→-FN|*FN|ε?
	?*?F→（E）|i?
	?*/

	/*
	?*?求First集和Follow集
	?*?
	?*?First（E）={（i}?	Follow（E）={）#}?
	?*?First（T）={（i}?	Follow（T）={+/#}
	?*?First（F）={（i}?	Follow（F）={-*#}?
	?*?First（M）={+/ε}?Follow（M）={）#}
	?*?First（N）={-*ε}?Follow（N）={+/#}
	?*/

	//?構造預測分析表
	private?String[]?Vt?=?{“+“?“/“?“-“?“*“?“（“?“）“?“i“};
	private?String[]?Vn?=?{“E“?“T“?“F“?“M“?“N“};
	private?String[][]?M?=?{?
			//+=0??		/=1?	-=2??	*=3??	（=4??	）=5??	i=6??	#=7
			{?““		““		““?	““?	“TM“?	““?	“TM“?	““}??	//E=0
			{?““		““?	““?	““?	“FN“?	““?	“FN“?	““}??	//T=1
			{?““		““?	““?	““?	“（E）“?	““?	“i“?	““}??	//F=2
			{?“+TM“	“/TM“?	““?	““?	“ε“?	““?	““?	“ε“}??	//M=3
			{?“ε“?		“ε“?	“-FN“?	“*FN“	““?	““?	““?	“ε“}	//N=4
	};
	
	//開始分析
	private?String[]?stack?=?new?String[256];
	private?String?stack_top;
	private?int?stack_ptr?=?-1;
	private?int?ptr?=?0;
	private?char?c_temp;
	private?int?Vt_code;
	private?int?Vn_code;
	private?void?get_char（String?sentence）{
		c_temp?=?sentence.charAt（ptr）;
		ptr++;
		if（c_temp?==?‘+‘）{
			Vt_code?=?0;
		}else?if（c_temp?==?‘/‘）{
			Vt_code?=?1;
		}else?if（c_temp?==?‘-‘）{
			Vt_code?=?2;
		}else?if（c_temp?==?‘*‘）{
			Vt_code?=?3;
		}else?if（c_temp?==?‘（‘）{
			Vt_code?=?4;
		}else?if（c_temp?==?‘）‘）{
			Vt_code?=?5;
		}else?if（c_temp?==?‘i‘）{
			Vt_code?=?6;
		}else?if（c_temp?==?‘#‘）{
			Vt_code?=?7;
		}
	}
	private?void?push（String?str）{
		stack_ptr++;
		stack[stack_ptr]?=?str;
	}
	private?void?pull（）{
		stack_top?=?stack[stack_ptr];
		stack[stack_ptr]?=?null;
		stack_ptr--;
		
		if（stack_top.equals（“E“））{
			Vn_code?=?0;
		}else?if（stack_top.equals（“T“））{
			Vn_code?=?1;
		}else?if（stack_top.equals（“F“））{
			Vn_code?=?2;
		}else?if（stack_top.equals（“M“））{
			Vn_code?=?3;
		}else?if（stack_top.equals（“N“））{
			Vn_code?=?4;
		}
	}
	private?boolean?isVt（String?str）{
		for（int?i?=?0;?i?			if（str.equals（Vt[i]））{
				return?true;
			}
		}
		return?false;
	}
	private?boolean?isVn（String?str）{
		for（int?i?=?0;?i?			if（str.equals（Vn[i]））{
				return?true;
			}
		}
		return?false;
	}
	public?boolean?SyntaxAnalyse（String?sentence）{
		
		push（“#“）;
		push（“E“）;
		get_char（sentence）;
		boolean?flag?=?true;
		while（flag）{
			pull（）;
			if（isVt（stack_top））{
				if（stack_top.equals（String.valueOf（c_temp）））{
					get_char（sentence）;
				}else{
					return?false;
				}
			}else?if（stack_top.equals（“#“））{
				if（stack_top.equals（String.valueOf（c_temp）））{
					flag?=?false;
				}else{
					return?false;
				}
			}else?if（M[Vn_code][Vt_code]?!=?null）{
				if（!M[Vn_code][Vt_code].equals（“ε“））{

?屬性????????????大小?????日期????時間???名稱
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????.CA....??????3818??2009-06-04?14:56??sa\LL1SA.java

?????目錄??????????0??2009-06-04?14:57??sa

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?????????????????3818????????????????????2