Question

In C++

9) (5 pts) Complete the following function that takes 3 arguments of a circle :

- radius (input argument)

- area (output argument, to be calculated)

- circumference (output argument, to be calculated)

All arguments are double type.

If a radius is negative, the function returns false, otherwise it returns true.

The function does only calculation, and does nothing else.

Assume that all #include are already there                                    

// Fill in your Function prototype

bool circleAreaAndCircumference ( _______, ________, __________);

int main() {

         double radius, area, circumference;

         cout << "Enter a circle radius:";

         cin >> radius;

         bool res =____________________ // call the function

         if (res)

    cout << "Area is " << area << endl << "Circumference is " << circumference << endl;

         else

    cout << "Invalid circle";

}

// Fill in your full function definition

//................

//

10) (4 pts) Given the following code

int num[30] = {2, 4, 6, 9, 5, -1, 7, 10};

Do not write any code.

Show the value of:

a. num[3] + num[4]

b. num[6]

c. num[9] + 1

d. num[30]

        

11) (6 pts) Suppose we want to have an array of 16 hexadecimal digits from '0', .....,'9', 'A',....'F'. Use one or two loops to fill data in the array. Fill in the ___ portion below:                                                                    

       char digits [ ___ ];   

// Write your loop and other code

    ......

      

12) (6 pts) Write a function to count the number of occurrences of a specific decimal digit in a string

// Function prototype     

int countDigit(int digit, string str) ;

For example, this function can be called like this:

int main() {

    string str = "12314561asd vd&*1";

    int digit = 1;

    int cnt = countDigit(1, str);

    // Expected output : Number of 1 in the string is 4

    cout << "Count of digit " << digit << " in the string is " << cnt;

}

Answer 1

////////////////////question 9

bool circleAreaAndCircumference (double radius, double *area, double *circumference);
int main() {
double radius, area, circumference;
cout << "Enter a circle radius:";
cin >> radius;
bool res =circleAreaAndCircumference (radius, &area, &circumference);
if (res)
cout << "Area is " << area << endl << "Circumference is " << circumference << endl;
else
cout << "Invalid circle";
return 0;
}

bool circleAreaAndCircumference (double radius, double *area, double *circumference)
{
if(radius<0)
return false;
else
{*area=3.14*radius*radius;
*circumference=2*3.14*radius;
return true;}
}

////////////////question 10

a) 9+5=14

b) 7

c) 0+1=1

d) 0

//////////question 11

for(int i=0;i<=9;i++)
digits[i]=c+i;
c='A';
for(int i=0;i<=5;i++)
digits[10+i]=c+i;

///////////question 12

int countDigit(int digit, string str) ;
int main() {

string str = "12314561asd vd&*1";

int digit = 1;

int cnt = countDigit(1, str);

// Expected output : Number of 1 in the string is 4

cout << "Count of digit " << digit << " in the string is " << cnt;

}
int countDigit(int digit, string str)
{
int count=0;
string dig=to_string(digit);
for(int i=0;i<str.length();i++)
if(dig[0]==str[i])
count++;
return count;
  
}