My code isn't working properly, can't find the error.

[CJM0929]

This code determines if the following brackets are balanced or not.

But for some reason in the third case, is marking it as unbalance and it supposed to be balanced.

#include <iostream>
#include "ArrayStack.h"
#include <string>
using namespace std;

// Function prototype
bool checkallBraces(char []);

int main()
{
	char * s;
	s = new char;
	string input;

	while (!(input == "q"))
	{
		cout << "This program checks if an expression is balanced.\nEnter expression: ";
		cin >> s;

		if (checkallBraces(s))
			cout << "Expression is balanced!\n";
		else
			cout << "Expression isn't balanced!\n";
	}
	system("pause");
	return 0;
}


bool checkallBraces(char s[])
{
	char ch = '\0';
	char stackItem = '\0';
	bool balancedSoFar = true;
	ArrayStack<char>* aStack = new ArrayStack<char>;

	// iterate through each character in the string while checking continue

	for (int i = 0; i < sizeof(s) && balancedSoFar; i++)
	{
		// set ch to current pos in string
		ch = s[i];

		// Ignore all characters but (, {, [, ], } and )
		if ((ch == ')') || (ch == '(') || (ch == '}') || (ch == '{') || (ch == ']') || (ch == '['))
		{
			// process open brace
			if (ch == '{' || ch == '(' || ch == '[')
			{ // el error estaba aqui
				aStack->push(ch);
			}

			// process closed brace
			else if (!aStack->isEmpty()) 
			{
				// peek into stack to find opening brace
				stackItem = aStack->peek();

				// try to match open and close delimiters of the same kind
				if (((ch == ')') && (stackItem == '(')) || ((ch == '}') && (stackItem == '{')) || ((ch == ']') && (stackItem == '[')))
					aStack->pop(); // Pop a matching open brace if found.
				else // No matching open brace, Open and close parenthesis are not of the same type
					balancedSoFar = false;
			}

			// Unmatched open and close parenthesis
			else
				balancedSoFar = false;
		}
	}

	 //return true if stack is empty and balanced
	if (aStack->isEmpty())
		return (true && balancedSoFar);

	// else it isn't blanced
	else return false;

OUTPUT

This program checks if an expression is balanced.
Enter expression:{}
Expression is balanced!

// OK! NO PROBLEM !

This program checks if an expression is balanced.
Enter expression:{a{bc}
Expression isn't balanced!

// OK! NO PROBLEM!

This program checks if an expression is balanced.
Enter expression:{a{b}c}
Expression isn't balanced!

CAN SOMEONE EXPLAIN ME WHY IT ISN'T BALANCE ?
IT SUPPOSED TO BE BALANCED!

[ne555]

don't yell.


for (int i = 0; i < sizeof(s) && balancedSoFar; i++)
`s' is a pointer,
sizeof is evaluated at compile time
so you may understand why you are not iterating the whole string.
you may use strlen(), check if s[i] is the terminator '\0' character, or use std::string that knows its size.


> ArrayStack<char>* aStack = new ArrayStack<char>;

ArrayStack<char> aStack; //construct an object
a.pop(); //use it as 

http://www.cplusplus.com/forum/general/138037/#msg731921

	char * s;
	s = new char;

you just reserved enough space for 1 character. You cannot even use cin>>s because it needs to write the terminator character.

You better use std::string

std::string input;
while( std::getline(std::cin, input) and input not_eq "q" ){ //getline() reads a whole line, including spaces
   //...
}

bool checkallBraces(const std::string &s){
   for (int i = 0; i < s.length() && balancedSoFar; i++)
}

[kevinkjt2000]

Your logic is correct. The third case passed when I ran your code.
http://cpp.sh/5tb2
I removed #include "ArrayStack.h" and used #include <vector> instead. Maybe something is wrong with ArrayStack?

[CJM0929]

Thanks for taking the time to help! The problem was sizeof(s), I change it to strlen() and it worked.