Cpp

firstSet/first.cpp → firstSet ( Compiler problem )/first.cpp

@@ -6,6 +6,7 @@
 #include <cstring>
 #include <algorithm>
 #include <set>
+#include <regex>
 using namespace std;
 
 int theNubmerOfRules;
@@ -20,9 +21,9 @@ string getTerminal(string currentRule, int stratFrom) {
 
 		if (isspace(currentRule[i]))
 			break;
-	
-			terminal += currentRule[i];
-			
+
+		terminal += currentRule[i];
+
 	}
 	return terminal;
 }
@@ -42,9 +43,9 @@ string getNonTerminal(string currentRule, int stratFrom) {
 }
 string firstTerminal(string currentRule, string productionsRules[]) {
 	string firstSet = "";
-	char TerminalOrNonTerminal = currentRule[currentRule.find('>')+2];
+	char TerminalOrNonTerminal = currentRule[currentRule.find('>') + 2];
 	int  IndexOfTerminalOrNonTerminal = currentRule.find('>') + 2;
-	
+
 	if (!isupper(TerminalOrNonTerminal)) {
 		//to guarantee epsilon in the correct pos.
 		if (currentRule.back() != '$' && TerminalOrNonTerminal == '$') {
@@ -55,11 +56,11 @@ string firstTerminal(string currentRule, string productionsRules[]) {
 		return firstSet;
 	}
 	else {
-	string nonTerminal = getNonTerminal(currentRule, IndexOfTerminalOrNonTerminal);
-	
+		string nonTerminal = getNonTerminal(currentRule, IndexOfTerminalOrNonTerminal);
+
 		for (int rule = 0; rule < theNubmerOfRules; rule++) {
-			string anotherNonTerminal = productionsRules[rule].substr(0, productionsRules[rule].find('-')-1);
-		
+			string anotherNonTerminal = productionsRules[rule].substr(0, productionsRules[rule].find('-') - 1);
+
 			if (nonTerminal == anotherNonTerminal) {
 				currentRule = productionsRules[rule];
 				firstSet += firstTerminal(currentRule, productionsRules) + " ";
@@ -70,63 +71,84 @@ string firstTerminal(string currentRule, string productionsRules[]) {
 	}
 	return firstSet;
 }
+int countNetminalOrNonterminal(string rule, regex x) {
+
+	sregex_iterator currentMatch(rule.begin(), rule.end(), x);
+	sregex_iterator lm;
+	string out = "";
 
+	int c = 0;
+	while (currentMatch != lm) {
+		smatch  match = *currentMatch;
+		++c;
+		currentMatch++;
+	}
+	return c;
+
+}
 set<string> getFirstSet(string NonTerminal) {
 
 	string currentRule;
 	set<string> firstSet;
-	
+
 	bool hasEpsilon = true;
 
 	for (int j = 0; j < theNubmerOfRules; j++) {
 		string anotherNonTerminal = productionsRules[j].substr(0, productionsRules[j].find('-') - 1);
-		if ( NonTerminal == anotherNonTerminal) {
-			 currentRule = productionsRules[j];
+		if (NonTerminal == anotherNonTerminal) {
+			currentRule = productionsRules[j];
+			regex b("[A-Za-z]+");
+
 			//No repetition
-				if (firstTerminal(currentRule, productionsRules).find("$") != firstTerminal(currentRule, productionsRules).npos && currentRule.size() != 6) {
-					char TerminalOrNonTerminal = currentRule[currentRule.find('>') + 2];
-					int  IndexOfTerminalOrNonTerminal = currentRule.find('>') + 2;
-
-					for (int i = IndexOfTerminalOrNonTerminal; i < currentRule.size(); i++) {
-						if (!isspace(TerminalOrNonTerminal)) {
-						//	cout << TerminalOrNonTerminal;
-								if (!isupper(TerminalOrNonTerminal)) {
-									if (firstSet.count(getTerminal(currentRule, i)) == 0)
-										firstSet.insert(getTerminal(currentRule, i));
-										hasEpsilon = false;
-										i += getTerminal(currentRule, i).size();
-										TerminalOrNonTerminal = currentRule[i];
-								}
-								else {
-									//to save from override
-									set<string> save = getFirstSet(getNonTerminal(currentRule, i));
-									firstSet.insert(save.begin(), save.end());
-
-									if (firstSet.count("$") != 0)
-										firstSet.erase("$");
-									else
-										hasEpsilon = false;
-
-									i += getNonTerminal(currentRule, i).size();
-									TerminalOrNonTerminal = currentRule[i + 1];
-
-								}
+			if (firstTerminal(currentRule, productionsRules).find("$") != firstTerminal(currentRule, productionsRules).npos && countNetminalOrNonterminal(currentRule, b) >= 3) {
+				cout << 55;
+				char TerminalOrNonTerminal = currentRule[currentRule.find('>') + 2];
+				int  IndexOfTerminalOrNonTerminal = currentRule.find('>') + 2;
+				for (int i = IndexOfTerminalOrNonTerminal; i < currentRule.size(); i++) {
+					if (!isspace(TerminalOrNonTerminal)) {
+						if (!isupper(TerminalOrNonTerminal)) {
+							if (firstSet.count(getTerminal(currentRule, i)) == 0)
+								firstSet.insert(getTerminal(currentRule, i));
+							hasEpsilon = false;
+							i += getTerminal(currentRule, i).size();
+							TerminalOrNonTerminal = currentRule[i];
+
+							break;
+						}
+						else {
+							//to save from override
+							set<string> save = getFirstSet(getNonTerminal(currentRule, i));
+							firstSet.insert(save.begin(), save.end());
+							if (firstSet.count("$") != 0)
+								firstSet.erase("$");
+							else {
+
+								hasEpsilon = false;
+								break;
+							}
+							i += getNonTerminal(currentRule, i).size();
+							if (i < currentRule.size())
+								TerminalOrNonTerminal = currentRule[i + 1];
+
+
 						}
-
 					}
-				}
 
-				else {
-					hasEpsilon = false;
-					firstSet.insert(firstTerminal(currentRule, productionsRules));
 				}
-
+			}
+
+			else {
+
+				hasEpsilon = false;
+				firstSet.insert(firstTerminal(currentRule, productionsRules));
+			}
+
 		}
 	}
 
 	if (hasEpsilon)
 		firstSet.insert("$");
-	
+
 	return firstSet;
 
 }
@@ -136,12 +158,12 @@ int main()
 	cin.ignore();
 	//get productions rules
 	for (int i = 0; i < theNubmerOfRules; i++)
-		getline(cin,productionsRules[i]);
+		getline(cin, productionsRules[i]);
 
 	multiset<string>visited;
 	for (int rule = 0; rule < theNubmerOfRules; rule++) {
 		string currentRule = productionsRules[rule];
-		string nonTerminal = getNonTerminal(currentRule,0);
+		string nonTerminal = getNonTerminal(currentRule, 0);
 		visited.insert(nonTerminal);
 		set<string> firstSet;