Stack_CheckBalance.cpp

#include <iostream>

using namespace std;
#define size 10

class stackexp {
    int top;
    char stk[size];
public:
    stackexp() {
        top = -1;
    }

    void push(char);

    char pop();

    int isfull();

    int isempty();
};

void stackexp::push(char x) {
    top = top + 1;
    stk[top] = x;
}

char stackexp::pop() {
    char s;
    s = stk[top];
    top = top - 1;
    return s;
}

int stackexp::isfull() {
    if (top == size)
        return 1;
    else
        return 0;
}

int stackexp::isempty() {
    if (top == -1)
        return 1;
    else
        return 0;
}

int main() {
    stackexp s1;
    char exp[20], ch;
    int i = 0;
    cout << "\n==========================Parenthesis Balancing==========================" << endl;
    cout << "\nEnter the expression to check whether it is in well form or not: ";
    cin >> exp;
    if ((exp[0] == ')') || (exp[0] == ']') || (exp[0] == '}')) {
        cout << "\nInvalid expression.";
        return 0;
    } else {
        while (exp[i] != '\0') {
            ch = exp[i];
            switch (ch) {
                case '(':
                    s1.push(ch);
                    break;
                case '[':
                    s1.push(ch);
                    break;
                case '{':
                    s1.push(ch);
                    break;
                case ')':
                    s1.pop();
                    break;
                case ']':
                    s1.pop();
                    break;
                case '}':
                    s1.pop();
                    break;
            }
            i = i + 1;
        }
    }
    if (s1.isempty()) {
        cout << "\nExpression is well parenthesis.";
    } else {
        cout << "\nInvalid expression or not in well parenthesized.";
    }
    return 0;
}