** On paper portion.
Points: 20 points total, 10 points for #1, 10 points for #2

Last Name:


First Name: 


Section (start time of your class): 



1) Run the algorithm.  Use the indicated algorithm to answer each question.
   Show your work.  No credit if you don't show your work.

1a) Use selection sort to sort the numbers  -1, 2, 4, 0, -2, 3, 1

-1, 2, 4, 0, -2, 3, 1
-2, 2, 4, 0, -1, 3, 1
-2, -1, 4, 0, 2, 3, 1
-2, -1, 0, 4, 2, 3, 1
-2, -1, 0, 1, 2, 3, 4













1b) Encrypt the message "farewell all" using the caesar cipher and
    password 5.

abcdefghijklmnopqrstuvwxyz

farewell all
kfwjbjqq fqq











1c) Convert the hexadecimal number D2 to decimal.

0123456789ABCDEF
          012345

D2 = 16*D + 1*2 = 16*13 + 2 = 210
D2 = 1101 0010 = 128 + 64 + 16 + 2 = 210








1d) Determine if the number 79 is prime.

sqrt(79) = 8.something
79/2 = 39, R 1
79/3 = 26, R 1
79/4 = 19, R 3
79/5 = 15, R 4
79/6 = 13, R 1
79/7 = 11, R 2
79/8 = 9, R 7

79 is prime














2) Be the computer.  For each, keep track of the values of all the variables
   as the code runs - as we did in class.  


2a) loops.

// code
int x=2, i=0, total=0;

while (x != 0) {
  i++; 
  total += x;
  if (x % 2 == 0) x = x / 2;
  else x = 2*(x - 1);

  if (i >= 10) break;
}


// variable values.
//
// i: 1, 2, 3
//
// x: 2, 1, 0
//
// total: 0, 2, 3
//







































2b) functions.

// code
int f1(int x, int y) {
  int temp = x;
  x = y;
  y = temp;
  return f2(x,y);
}
int f2(int z, int w) {
  int temp = w;
  w = z;
  z = temp;
  return w;
}
int main() {
  int x=1, y=2, z=3;
  x = f1(y, z);
  y = f2(x, z);
}

// variable values.
//
// x in main: 1, 3
//
// y in main: 2, 3
//
// z in main: 3
//
// temp in f1: 2
//
// x in f1: 2, 3
//
// y in f1: 3, 2
//
// temp in f2: 2; 3
//
// z in f2: 3, 2; 3
// 
// w in f2; 2, 3 (returned); 3








2c) arrays.

// code
char msg[10] = "hello";
int i;
for(i=0; i<5; i++) {
  msg[i] = msg[i] + 1;
}
for(i=0; i<4; i++) {
  msg[i] = msg[i+1];
}


// variable values.
//
// i: 0, 1, 2, 3, 4, 5; 0, 1, 2, 3, 4
//
// msg: "hello",        "ifmmp"
//      "iello",        "ffmmp"
//      "ifllo",        "fmmmp"
"       "ifmlo",        "fmmmp"
//      "ifmmo",        "fmmpp"
//      "ifmmp"
//