b) Given the class ArrayStack, write a full program that would take in an arbitrary string of parentheses, curly braces, and square braces, and outputs if the string is balanced or not. The string is said to be balanced if all opening elements have a matching closing element of the same type. e.g. The string ( [ ] { } { } { ( ) } ) would be considered balanced, but ( { ) [ ( ] ) ) would not. Refer to Section 5.1.7 (pg 204-205) in your textbook for the algorithm.

Answer:

#include

#include

#include "ArrayStack.h"

int main( ) {

// set up the stack, string, and flag variables

ArrayStack checker;

string input = "";

bool unbalanced = false;

// get the string

cin >> input;

// run through the loop

for (int i =0; i < input.length() && !unbalanced; i++) {

// Your code goes here.

}

// report to the user

cout << "The string is " << (unbalanced ? "unbalanced" : "balanced") << endl;

return 0;

}

#pragma once // Code based on:

// Data Structures and Algorithms in C++, Goodrich, Tamassia, and Mount, 2nd Ed., 2011.

//

#pragma once #include

using namespace std;

template

class ArrayStack { enum { DEF_CAPACITY = 100 }; // default stack capacity

public: ArrayStack(int cap = DEF_CAPACITY); // constructor from capacity int size() const; // number of items in the stack bool empty() const; // is the stack empty? const E& top() const; // get the top element void push(const E& e); // push element onto stack void pop(); // pop the stack void printAll(); // print all elements on stack to cout

private: // member data E* S; // array of stack elements int capacity; // stack capacity int t; // index of the top of the stack };

template ArrayStack::ArrayStack(int cap)

: S(new E[cap]), capacity(cap), t(-1) { } // constructor from capacity

template int ArrayStack::size() const

{ return (t + 1); } // number of items in the stack

template bool ArrayStack::empty() const

{ return (t < 0); } // is the stack empty?

template // return top of stack

const E& ArrayStack::top() const { if (empty()) throw length_error("Top of empty stack"); return S[t]; }

template // push element onto the stack

void ArrayStack::push(const E& e) { if (size() == capacity) throw length_error("Push to full stack"); S[++t] = e; }

template // pop the stack

void ArrayStack::pop() {

if (empty()) throw length_error("Pop from empty stack"); --t;

}

// print all elements on stack

template

void ArrayStack::printAll() {

if (empty()) throw length_error("Empty stack"); cout << "Elements in stack: "; for (int i = t; i >= 0; i--) { cout << "{" << S[i] << "} "; } cout << endl;

}