adding cs235

cs235/lab04/expman.h

@@ -0,0 +1,28 @@
+#ifndef __EXPMAN_H__ 
+#define __EXPMAN_H__
+#include <iostream>
+#include <stack>
+#include <vector>
+#include <cstdlib>
+#include <sstream>
+#include <string>
+#include "ExpressionManagerInterface.h"
+
+using namespace std;
+
+class expman : public ExpressionManagerInterface {
+	public:
+        bool isBalanced(string expression);
+        string postfixToInfix(string postfixExpression);
+        string infixToPostfix(string infixExpression);
+        string postfixEvaluate(string postfixExpression);
+};
+
+int precedence(string ch);
+bool is_paren(string token);
+bool is_int(string token);
+bool is_valid_expression(string token);
+bool is_valid_token(string token);
+stack<string> reverse_stack(stack<string>);
+stack<string> parse_expression(string);
+#endif