Question

"Controlling complexity is the essence of computer programming." Write a program that uses the C++ string functionality to count the number of vowels in this phrase. Q7. Write a function bool xor(bool A, bool B) which returns the Exclusive OR of boolean input variables A and B. Test your function by printing out the full truth table of the function. Q8. Write a method swap(char_all, int i, int i) which swaps element i and element j of a given character array a[). Q9. Write a method reverseString(char s[], int len) which reverses the elements of the character string s. The length of the string is given by the value of “len”. Your implementation must use your swap function of Q8. Q10. Write a C++ class called Dice. A Dice can be rolled, so that it takes on a new random value 1,2,3,4,5 or 6. A Dice also has a get() method which returns the current value of the dice. Write a programme that makes two Dice objects, rolls each of them and prints out the sum of the values. Now write a programme (e.g. inside main()) that makes two Dice and estimates the probability that the sum of two Dice is greater than 6 (by averaging the results of a large number of rolls).

Answer 1

Q6.

#include <iostream>

#include<string.h>

using namespace std;

// code to count the vowles

int main() {

    // phrase

string phrase = "Controlling complexity in essence of computer programming.";

    // use length function to get the length of the string

int len = phrase.length();

    // intitialize the variable count_vowel to store the count

int count_vowel = 0;

    // now loop through each character in the string and check if they are vowels or not

for(int i = 0; i < len; i++) {

        // if the character is vowels then add 1 to count_vowel

if (tolower(phrase[i]) == 'a' || tolower(phrase[i]) == 'e' || tolower(phrase[i]) == 'i' || tolower(phrase[i]) == 'o' || tolower(phrase[i]) == 'u') {

count_vowel += 1;

}

}

    // display the result

cout << "following phrase: " << phrase << endl;

cout << "has " << count_vowel << " vowels." << endl;

return 0;

}

Q7.

// function to output the result of xor of A and B

/// input is bool values A and B

// output is a bool A xor B

bool bool_xor(bool A, bool B) {

    // if the both inputs are same we return false

    if (A == B) {

        return false;

    }

    // else we return true

    return true;

}

Q8.

// function to swap the character in the array

// input are: a characyer array, int i and int j

// function outputs nothing

void swap_char(char a[], int i, int j) {

    // store the element at ith position in variable c

    char c = a[i];

    // now copy the jth element to ith position

    a[i] = a[j];

    // now assign c to jth position

    a[j] = c;

}

Q9.

// function to reverse the string using the swap char function

// inputs are char array and length of array

// output is nothing

void reverseString(char s[], int len) {

    // initialize j

    int j = len-1;

    

    // loop from start to middle of the string

    for(int i = 0; i < len / 2; i++) {

        // call function to swap the characters

        swap_char(s, i, j-i);

    }

}