1.1 Exercises  (Page 4/8)

14. Write and run a program that reads three strings and prints them out in an alphabetical order. (Hint: Use the strcmp() function).

15. Modify the program in Section Array of Structures to compute and display the average rate of the five first employees.

16. The following program reads a set of name, roll number, sex, height and weight of the students from the keyboard using a structure within an array.

#include<iostream.h>

#include<string.h>

const int MAX = 100

struct student{

char name[20];

long int rollno;

char sex;

float height;

float weight;

};

void main(){

student cls[MAX];

int i,n;

cout<<“ How many names ? \n“;

cin>>n;

for( i = 0; i<= n-1; ++i){

cout<<“record = “<<i+1<<endl;

cout<<“name : “; cin>>cls[i].name;

cout<<“rollno : “; cin>>cls[i].rollno;

cout<<“sex : “; cin>>cls[i].sex;

cout<<“height : “; cin>>cls[i].height;

cout<<“weight : “; cin>>cls[i].weight;

cout>>endl;

}

……

}

Include into the above program the code that performs two tasks:

a. displaying data of n students in the following format:

b. computing and displaying the average of heights and the average of weights of the students.

Exercise 6

1. a. Write a function inorder that determines whether the three characters are in alphabetic order or not. It returns true if the three arguments are in order or false otherwise.

b. Write a complete program that reads three characters and calls the function inorder to report whether they are in alphabetic order, loops until reading “***”.

2. a. Write a function IntSquare that computes the greatest integer so that its square is less than or equal to a given number.

b. Write a complete program that reads an integer n and invokes the function IntSquare to compute the greatest integer so that its square is less than or equal to n.

3. a. Write a function that computes the fourth root of its integer argument k. The value returned should be a double. (Hint: Use the library function sqrt()).

b. Write a complete program that reads an integer n and invokes the function to compute the fourth root of n.

4. a. Write a function is_prime(n) that returns true if n is a prime or false, otherwise.

b. Write a complete program that reads an integer n and invokes the function to check whether n is prime.

5. We can recursively define the number of combinations of m things out of n, denote C(n, m), for n>= 1 and 0<= m<= n, by

C(n,m) = 1 if m = 0 or m=n

C(n, m) = C(n-1, m) + C(n-1, m-1) if 0<m<n

1. Write a recursive function to compute C(n, m).
2. Write a complete program that reads two integers N and M and invokes the function to compute C(N, M) and prints the result out.

6. Given a function as follows:

int cube(int a)

{

a = a*a*a;

return a;

}

1. Write a complete program that reads an integer n and invokes the function to compute its cube.
2. Rewrite the function so that the parameter is passed by reference. It is named by cube2. Write a complete program that reads an integer n and invokes the function cube2 to compute its cube, prints the result out and then displays the value of n. What is the value of n after the function call?

7. a. Write a function that can find the largest element in the array that is passed to the function as a parameter.