正规文法转换成正规式(C++)

1、精选优质文档-倾情为你奉上#include <iostream>#include <set>#include <map>#include <string>#include <algorithm>using namespace std;multimap<char, string> production;set<char> unFinal;set<char>final;char S;void Input()char ch;string str;cout<<"非终结符（以 0 结尾）

2、： "while(cin>>ch && ch!='0') unFinal.insert(ch);cout<<"终结符 （以 F 结尾）： "while(cin>>ch && ch!='F')final.insert(ch); cout<<"开始符: "cin>>S;cout<<"产生式 (以 0 0 结尾):"<<endl;while(cin>>ch>>s

3、tr && ch!='0')production.insert(make_pair(ch, str);string solve(char ch)string str("(");string re("");string ch_18;string str18,str28;int len,i,j,flag=10,strlen,sslen,lslen,num=0;multimap<char, string>:iterator iter = production.find(ch);int n = production.c

4、ount(ch);for(i=0; i<n; i+, +iter) len=iter->second.size();str1i.append(iter->second);str2i=str1i;str2i.replace(1,1,"|");ch_1i=iter->second.substr(len-1);for(i=0; i<n; i+) if(ch_1i>="A"&&ch_1i<="Z") for( j=i+1;j<n;j+)if(ch_1i=ch_1j) flag=i

5、;str.push_back('(');str.append(str2i.substr(0); str.append(str2j.substr(0);for( ;j<n;j+)str1j.assign(str1j+1);ch_1j.assign(ch_1j+1); if(i=flag)strlen=str.size(); str.replace(strlen-1,1,")"); str.append(ch_1i); str.push_back('|');else str.append(str1i.substr(0);if(n>=2

6、)/相同左部产生式个数大于等于2个时，才输出"|" str.push_back('|'); sslen=str.size();for(i=0; i<n; i+) if(ch_1i<"A"|ch_1i>"Z")num+;if(num>=2)str.push_back('(');for(i=0; i<n; i+) if(ch_1i<"A"|ch_1i>"Z")str.append(ch_1i);if(i!=n-1) str.p

7、ush_back('|');if(num>=2)str.push_back(')');lslen=str.size(); for(int i=0; i<str.size(); i+)if(unFinal.find(stri)!=unFinal.end() /stri是非终结符if(stri != ch) /是其他非终结符re = solve(stri);str.replace(i, 1, re);i += re.size()-1;/下标后移 Notice！else /此非终结符就是chstr.replace(i, 1, "*");str.replace(sslen-1,lslen-sslen+1,str.substr(sslen); str.push_back(')');return str;int main()Input();cout<<endl<<"输出正规式