Answer:
23. Write a function named "g_c_d" that takes two positive integer arguments and returns as its value
the greatest common divisor of those two integers. If the function is passed an argument that is not
positive (i.e., greater than zero), then the function should return the value 0 as a sentinel value to
indicate that an error occurred. Thus, for example,
cout << g_c_d(40,50) << endl; // will print 10
cout << g_c_d(256,625) << endl; // will print 1
cout << g_c_d(42,6) << endl; // will print 6
cout << g_c_d(0,32) << endl; // will print 0 (even though 32
is the g.c.d.)
cout << g_c_d(10,-6) << endl; // will print 0 (even though 2 is
the g.c.d.)
24. A positive integer n is said to be prime (or, "a prime") if and only if n is greater than 1 and is
divisible only by 1 and n . For example, the integers 17 and 29 are prime, but 1 and 38 are not
prime. Write a function named "is_prime" that takes a positive integer argument and returns as its
value the integer 1 if the argument is prime and returns the integer 0 otherwise. Thus, for example,
cout << is_prime(19) << endl; // will print 1
cout << is_prime(1) << endl; // will print 0
cout << is_prime(51) << endl; // will print 0
cout << is_prime(-13) << endl; // will print 0
25. Write a function named "digit_name" that takes an integer argument in the range from 1 to 9 ,
inclusive, and prints the English name for that integer on the computer screen. No newline character
should be sent to the screen following the digit name. The function should not return a value. The
cursor should remain on the same line as the name that has been printed. If the argument is not in the
required range, then the function should print "digit error" without the quotation marks but followed by
the newline character. Thus, for example,
the statement digit_name(7); should print seven on the screen;
the statement digit_name(0); should print digit error on the screen and place
the cursor at the beginning of the next line.Explanation:
