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Points... 25 points total.
(1) is worth 5 points.  (2) 10 points.  (3) 6 points.  (4) 4 points.


(1) Give C code to (a) ask the user how many numbers they want to
    enter, (b) ask the user for those integers, and (c) compute and
    print the average of all the numbers entered.  Use correct
    spelling (including upper/lower case) and punctuation.  Give the 
    complete program, including the #include's.
#cindsalfkjalsjdf

int main() {
  printf("How many? ");
  int n, N;
  scanf("%i",&n); N = n;

  double total=0, num;
  for(; n > 0; n--) {
    printf("Num: ");
    scanf("%lf", &num);
    total += num;
  }

  printf("%lf\n", total / N);
  return 0;
}

















(2) Random questions about C.  
    For questions about syntax, give the exact correct spelling/capitalization 
    (e.g., int, not Integer or integer).

(2a) What are the two types that can be used to store floating point 
     numbers in C, and what is the difference between them?

double - 64 bits
float - 32 bits



(2b) Name 3 different types that are used in C to store integers, and 
     what is the difference between them?

char - 1 byte
short - 2 bytes
int - 4 bytes
long - 8 bytes
unsigned any of those




(2c) What are the smallest and largest possible values of a signed
     char?  Of an unsigned char?  Of an int?
unsigned ... 2^(# bits) - 1
signed ... -2^(# bits - 1) -> 2^(# bits - 1) - 1



(2d) Write how you would declare a pointer to an integer in C.

int *x;



(2e) Evaluate each of the following:
     30 in binary is 11110
     13 in binary is 01101

     30 & 13 = 01100 = 12

     30 && 13 = 1

     30 | 13 = 11111 = 31 

     30 || 13 = 1

     30 ^ 13 = 10011 = 19


     



(3) What does the code do?  For each, keep track of what the values of
    the variables are, and the final printed result.



(3a) Functions and pointers
void fun(int *x, int *y, int z, int w[]) {
  z = *x;
  *x = *y;
  *y = z;
  w[0] = *x; w[1] = *y; w[2] = z;
}


int main() {
  int a=1, b=2, c=3, 
      d[3] = {4, 5, 6};
  fun(&a, &b, c, d);
  
  printf("%i, %i, %i, %i\n", a, b, c,d[1]);
}

/*
Variables: 









Printed on screen: 

*/






(3b) Arithmetic
int x = 3, y = 2;
float z = x * y;
x = x + y * 3;
y = y / 3 + y;
y = (x + y) % 4;
z = z / 4.0;
printf("%i\n%i\n%f\n", x, y, z);

// x: 
//
// y: 
//
// z: 

// Printed on Screen: 












(3c) Loops
int i = 0;
int x = 200;
printf("%i, %i\n", i, x);
for(; i*i <= 16; i++) {
  printf("%i, %i\n", i, x);
  x /= 2;
}
printf("%i, %i\n", i, x);

// i: 
//
// x: 
//

// Printed on Screen: 






(4) Random questions from the "CS Memorize" document...  NOTE: for
    this problem, ^ is exponentiation even though ^ is not
    exponentiation in C.  For example, for this problem, 2^3 is 2*2*2 = 8.

(4a) Give the exact value for the sum 1 + 2 + 3 + ... + 50.




(4b) Give the exact value for the sum 1 + 1/3 + 1/9 + 1/27 + ... + 1/(3^10)




(4c) How many megabytes are in one gigabyte?  How many megabytes are in 
     one terabyte?



(4d) What is the value of log, base 2, of (2^10) ?