Homework 3
Due Monday, September 30, 2002
Solutions

a. int true; 
   "true" is a keyword, so you can't use it as a variable name.

b. const int conversion_factor(1.61);  
   conversion_factor should be stored as a float rather than an int

c. int acct_balance = 32,167;  
   commas cannot be used in variable initializations/values

d. cout << "Thank you for using this program!\endl";  
   It looks like they're mixing up endl with \n.  It should be either
   cout << "Thank you for using this program!" << endl;  
   or
   cout << "Thank you for using this program!\n";  

e. num1*num2=ratio; 
   ratio should be on the left hand side with num1*num2 on the right hand side
   (the left-hand-size should refer to a variable)

f. double hour;  
   In this example, the hour must be stored as an int, because we are using
   it with the % operator

g. cout << "Please enter your name" needs a semicolon
   The semicolon at the end of the line is missing
   
h. if (age < 18); 
   There shouldn't be a semi-colon at the end of the line

7) c is (3%4)*6, or 18
   d is then 18/4 or 4 (integer division - the remainder is truncated)
   lastly, e is (3+4+18+4)/4 or 29/4, or 7 (again, the remainder is truncated)

13) x = 20  (17 + 15/4 or 17 + 3 or 20)
    y = 15  (its value never was changed)
    z = 6   (20%3+4 = 2+4 = 6)
    w = 11.5 (17/3 + 6.5, or 5+6.5 or 11.5, no truncation since w is a double)
    t = 4.5  (20/4.0 + 15%4 - 3.5 = 5 + 3 - 3.5 = 4.5)

15c) 37.6 (13/5.0 + 2*17.5)
15e) 10   (17%5+13-5 = 2+13-5)

18b) const char Blank = ' ';
     const int one = 5;
     int main()
     {
	int a, b, cc;
	a = one + 5;
	b = a + Blank;
	cc = a + one * 2;
	b = a + cc;
	cout << "a = " << a << ", b = " << b << ", cc = " << cc << endl;
	
	return 0;
     }

19a) x *= 2;
19b) x += y - 2; 
19c) sum += num;
19d) z *= (x+2);
19e) y /= (x+5);

21)  a  b  c
     9  7  UND
     9  8  26
     10 45 27

22)  a   b   c   sum
     3   5  14.1 22
     3   5   4.7 22
     3   6   4.7 22
     50  6   4.7 22

2a) (i) Hello There
2c) (ii) 3

5) if(score >= 60)
	cout << "You pass." << endl;
   else
	cout << "You fail." << endl;