Question

C++

1. Write a function decimalToBinary() that takes in a positive integer as a parameter and use as stack to convert the integer to a its corresponding binary representation. Hint: divide the integer by 2.

2. A palindrome is a string of characters (a word, phrase, or sentence) that is the same regardless of whether you read it forward or backward—assuming that you ignore spaces, punctuation, and case. For example, Race car is a palindrome. So is A man, a plan, a canal: Panama. Write a function isPalindrome() that takes a string as a parameter and uses a stack to test whether a string is a palindrome.

3. Suppose that you read a binary string—that is, a string of 0s and 1s—one character at a time. Write a function that use a stack but no arithmetic to see whether the number of 0s is equal to the number of 1s. When these counts are not equal, show which character—0 or 1—occurs most frequently and by how much its count exceeds the other’s.

4. Write a program to test the four functions above.

Answer 1

Code

#include <bits/stdc++.h> //includes the stack and all necessary header diles

using namespace std;

//dispay the binary of a number

void decimalToBinary(int num)

{

    stack<int> s;   //define a stack

    int tnum = num; //copy the number

    while (tnum > 0)

    {

        s.push(tnum % 2);

        tnum = tnum / 2;

    }

    cout << "The binary of " << num << " is : ";

    //now print the stack contents

    while (!s.empty())

    {

        cout << s.top();

        s.pop();

    }

}

//isPalindrome method

void isPalindrome(string s)

{

    stack<char> st;

    for (int i = 0; i < s.length(); i++)

        if (isalnum(s[i]))

            st.push(s[i]);

    //now check the character

    for (int i = 0; i < s.length(); i++)

    {

        if (!isalnum(s[i]))

            continue;

        if (tolower(s[i]) != tolower(st.top()))

        {

            cout << "\n"

                 << s << " is not palindrome\n";

            return;

        }

        st.pop();

    }

    cout << "\n"

         << s << " is palindrome\n";

}

//checkString method

void checkString()

{

    //input a string from user

    string s;

    cout << "\nEnter a binary string : ";

    cin >> s;

    stack<char> s1, s2;

    for (int i = 0; i < s.length(); i++)

    {

        if (s[i] == '0')

            s1.push(s[i]);

        else

            s2.push(s[i]);

    }

    if (s1.size() > s2.size())

    {

        cout << "\n0's are more than 1's by " << (s1.size() - s2.size());

    }

    else if (s2.size() > s1.size())

    {

        cout << "\n1's are more than 0's by " << (s2.size() - s1.size());

    }

    else

        cout << "\nNumber of 1's and 0's are same";

}

//driver code of the program

int main()

{

    //call decimalToBinary() method

    decimalToBinary(19);

    //call the isPalindrome method

    isPalindrome("Race car");

    //call checkString method

    checkString();

}

Screesnhot

Output