create stackApp, which includes convertion of number system, and parenthesis matching.

thu_dsa/chp4/stackApp.cpp

@@ -0,0 +1,55 @@
+#include "../chp2/Fib.h"
+#include "stackApp.h"
+
+/*
+* @brief : convert a decimal digit n to any base(2 <= base <= 36)
+* @args  :
+* @return: return the result in the form of char*
+*/
+char* convert(__int64 n, int base){
+	Stack<char> charStack;
+	while(n != 0){
+		charStack.push(digits[n % base]);
+		n /= base;
+	}
+	char* res = new char[charStack.getSize() + 1];
+	int pos = 0;
+	while (!charStack.empty()) res[pos++] = charStack.pop();
+	res[pos] = '\0';
+	return res;
+}
+
+/*
+* @brief : to judge if an expression of matches
+* @args  : exp
+* @return: return true if matches
+*/
+bool paren(const char exp[]){
+	Stack<char> parenStack;
+	char currParen, popped;
+	for(int ix = 0; (currParen = exp[ix]) != '\0'; ++ix){
+		switch(currParen){
+		case '(':
+		case '[':
+		case '{':
+			parenStack.push(currParen);
+			break;
+
+		case ')':
+			if (parenStack.empty()) return false;
+			if (parenStack.pop() != '(') return false;
+			break;
+
+		case ']':
+			if (parenStack.empty()) return false;
+			if (parenStack.pop() != '[') return false;
+			break;
+
+		case '}':
+			if (parenStack.empty()) return false;
+			if (parenStack.pop() != '{') return false;
+			break;
+		}
+	}
+	return parenStack.empty()? true : false;
+}