Practical_25(C++).cpp

/*
A palindrome is a string of character that‘s the same forward and backward. Typically, punctuation, capitalization, 
and spaces are ignored. For example, “Poor Dan is in a droop” is a palindrome, as can be seen by examining the characters
“poor danisina droop” and observing that they are the same forward and backward. One way to check for a palindrome is to reverse
the characters in the string and then compare with them the original-in a palindrome, the sequence will be identical. Write C++ program 
with functions- 
a) To print original string followed by reversed string using stack 
b) To check whether given string is palindrome or not
*/

#include<iostream>
#include<string.h>
#define max 50
using namespace std;

class STACK {
private:
    char a[max];
    int top;

public:
    STACK() {
        top = -1;
    }

    void push(char);
    void reverse();
    void convert(char[]);
    void palindrome();
};

void STACK::push(char c) {
    top++;
    a[top] = c;
    a[top + 1] = '\0';

    cout << endl << c << " is pushed on stack ...";
}

void STACK::reverse() {
    char str[max];

    cout << "\n\nReverse string is : ";

    for (int i = top, j = 0; i >= 0; i--, j++) {
        cout << a[i];
        str[j] = a[i];
    }

    cout << endl;
}

void STACK::convert(char str[]) {
    int j, k, len = strlen(str);

    for (j = 0, k = 0; j < len; j++) {
        if (((int)str[j] >= 97 && (int)str[j] <= 122) || ((int)str[j] >= 65 && (int)str[j] <= 90)) {
            if ((int)str[j] <= 90) {
                str[k] = (char)((int)str[j] + 32);
            } else {
                str[k] = str[j];
            }

            k++;
        }
    }
    str[k] = '\0';

    cout << endl << "Converted String : " << str << "\n";
}

void STACK::palindrome() {
    char str[max];
    int i, j;

    for (i = top, j = 0; i >= 0; i--, j++) {
        str[j] = a[i];
    }
    str[j] = '\0';

    if (strcmp(str, a) == 0)
        cout << "\n\nString is palindrome...";
    else
        cout << "\n\nString is not palindrome...";
}

int main() {
    STACK stack;

    char str[max];
    int i = 0;

    cout << "\nEnter string to be reversed and checked if it's palindrome or not: \n\n";

    cin.getline(str, 50);

    stack.convert(str);

    while (str[i] != '\0') {
        stack.push(str[i]);
        i++;
    }

    stack.palindrome();

    stack.reverse();
}