Directions: Fill in answers on the pages below. Don't spend too much time on any one problem.
Points for each problem: 1-15, 2-15, 3-20, 4-20, 5-25, 6-20, 7-20, 8-25.

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1. if-else: Suppose a variable temperature is supposed to be in the range from 96.0 to 100.6 inclusive. Write a short piece of C code (not an entire program or even a function) that will print the message "Temperature OK" in case the temperature is in range and will print "You are sick" in case the temperature is out of range.

   double temperature = 98.6; /* or = 104.2 or = 94.0 */
   /* put the rest of the code below */
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

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2. loops: Rewrite the following for loop as a while loop that will print the same thing.

   int i;
   for (i = 1; i < 10; i++) {
      printf("%i squared = %i\n", i, i*i);
   }
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

3. Arrays: Given the two arrays a and b below, use a loop to let c be the sum of a and b, that is, each element of c is the sum of the corresponding elements of a and b. Then print the elements of c. (You must use loops for both parts.)

   #include <stdio.h>
   
   int main() {
      int a[] = {2, 6, 4, 7, 3, 9};
      int b[] = {5, 1, 3, 2, 4, 0};
      int c[6];
      /* give code that will let c be the */
      /*  coordinate-wise sum of a and b */
      
      
      
   
      
      
      
      
      
   
      /* give code to print the elements of c on one line, spaces between them */
      
      
      
   
   
   
      
      
   
   }
   

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4. Arrays as parameters: Write a function average with parameters a 1-dimensional array of integers and the size of the array. This function should find the average of the array elements (sum of the elements divided by the number of them). average should return this number as a double. For example, the main function below should print 90.0. Your function must use a loop and must work for an array of any size greater than 0.

   #include <stdio.h>
   /* prototype for function average here */
   
   
   int main() {
      int n = 3;
      int a[] = {90, 100, 80};
      /* complete the call below */
      double ave = average(a, n);
      printf("Average: %8.2f\n", ave);
   }
   
   /* definition of ave function here */
   
   
   
   
   
   
   
   
   
   
   
   
   

5. Series: Write a function series that will calculate the sum of n terms of the following series:

   1 - 1/22 + 1/32 - 1/42 + 1/52 - ...
     

   Notice that the signs are alternating. Your function should have the integer n as a formal parameter, and it should then use a loop to calculate the sum and to return that as the answer. For example, the call series(2) should return the number 1 - 1/2² = 1 - 0.25 = 0.75.

   #include <stdio.h>
   /* function series prototype here */
   
   
   int main() {
      double sum = series(100000);
      printf("%18.14f\n", sum);
   }
   
   /* definition of series function here */
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

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6. Pointers:
   1. What will the program below print?

   2. Use pointers and make alterations so that the program below will print 2006. (Do not introduce any new variable names.)

   
   
   #include <stdio.h>
   
   void newyear(int  p);
   
   int main() {
      int n = 2005;
   
      newyear( n);
   
      printf("After call to newyear, n = %i\n", n);
      
   }
   
   void newyear(int p) {
   
      p = 2006;
      
   }
   
   
   
   

7. structs: Use the definition of a struct in the code below.
   • Inside the main function below, declare two structs named george and martha.
   • By any means initialize george to be 37 year old, a Male, weighing 205 pounds.
   • Write a printf statement that will print these fields in the form:
     age: 37, sex: M, weight: 205.0
   • Assuming martha has been initialized (but you don't need to do this), write a expression that will give the sum of the weights of george and martha.

   #include <stdio.h>
   struct person {
      int age;       /* in years */
      char sex;      /* sex (M or F) */
      double weight; /* in pounds */
   };
   
   
   int main() {
      double sum_of_weights;
      /* answers to 5 parts above here */
   
   
   
      
   
   
   
   
   
   
   
   
   
   
   
   
   
      sum_of_weights =
      
      
   }
   
   

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8. Everything: Consider the following complete program:

   Deck of cards

   First part of output

   /* 1 */ #include <stdlib.h> /* 2 */ #include <time.h> /* 3 */ /* 4 */ struct card { /* single card */ /* 5 */ char suit; /* suit */ /* 6 */ int value; /* value (spots) */ /* 7 */ }; /* 8 */ void printdeck(struct card deck[]); /* 9 */ /* 10 */ int main() { /* 11 */ // deck of 52 cards /* 12 */ struct card deck[52]; /* 13 */ struct card temps; /* 14 */ /* 15 */ double ran[52]; /* 16 */ int i, dum; /* 17 */ /* 18 */ /* 19 */ // initialize deck /* 20 */ for (i = 0; i < 52; i++) { /* 21 */ deck[i].suit = i/13; /* 22 */ deck[i].value = i%13 + 1; /* 23 */ } /* 24 */ /* 25 */ // print the deck /* 26 */ printdeck(deck); /* 27 */ /* 28 */ srand((long)time(NULL)); /* 29 */ for (i = 0; i < 52; i++) /* 30 */ ran[i] = rand()/(double)RAND_MAX; /* 31 */ /* 32 */ for (dum = 0; dum < 51; dum++) /* 33 */ for (i = 0; i < 51; i++) /* 34 */ if (ran[i] < ran[i+1]) { /* 35 */ // interchange ran array elts /* 36 */ double temp = ran[i]; /* 37 */ ran[i] = ran[i+1]; /* 38 */ ran[i+1] = temp; /* 39 */ /* 40 */ // interchange deck array elts /* 41 */ temps = deck[i]; /* 42 */ deck[i] = deck[i+1]; /* 43 */ deck[i+1] = temps; /* 44 */ } /* 45 */ /* 46 */ // print the deck /* 47 */ printdeck(deck); /* 48 */ } /* 49 */ /* 50 */ void printdeck(struct card deck[]) { /* 51 */ int i, v, s; /* 52 */ printf("Deck of cards:\n"); /* 53 */ for(i = 0; i < 52; i++) { /* 54 */ v = deck[i].value; /* 55 */ if (v == 1) printf(" A"); /* 56 */ else if (v == 13) printf(" K"); /* 57 */ else if (v == 12) printf(" Q"); /* 58 */ else if (v == 11) printf(" J"); /* 59 */ else printf("%2i", deck[i].value); /* 60 */ printf(" of "); /* 61 */ s = deck[i].suit; /* 62 */ if (s == 0) printf("Spades"); /* 63 */ else if (s == 1) printf("Hearts"); /* 64 */ else if (s == 2) printf("Clubs"); /* 65 */ else if (s == 3) printf("Diamonds"); /* 66 */ printf("\n"); /* 67 */ } /* 68 */ printf("\n"); /* 69 */ }

   Deck of cards: A of Spades 2 of Spades 3 of Spades 4 of Spades 5 of Spades 6 of Spades 7 of Spades 8 of Spades 9 of Spades 10 of Spades J of Spades Q of Spades K of Spades A of Hearts 2 of Hearts 3 of Hearts 4 of Hearts 5 of Hearts 6 of Hearts 7 of Hearts 8 of Hearts 9 of Hearts 10 of Hearts J of Hearts Q of Hearts K of Hearts A of Clubs 2 of Clubs 3 of Clubs 4 of Clubs 5 of Clubs 6 of Clubs 7 of Clubs 8 of Clubs 9 of Clubs 10 of Clubs J of Clubs Q of Clubs K of Clubs A of Diamonds 2 of Diamonds 3 of Diamonds 4 of Diamonds 5 of Diamonds 6 of Diamonds 7 of Diamonds 8 of Diamonds 9 of Diamonds 10 of Diamonds J of Diamonds Q of Diamonds K of Diamonds

   The output shown is not the entire output of this program. Even if you didn't study or see this example, you still should be able to answer some of the questions below:

   1. What is line 15 doing?

       

       

   2. What are lines 28-30 doing?

       

       

       

   3. What different integers are stored in the value field of the struct?

       

       

       

   4. What different integers are stored in the suit field of the struct?

       

       

       

   5. What are lines 32-44 doing?

       

       

       

   6. What will the rest of the output look like? (The "second part" of the output that is not shown.)

       

       

       

   7. If we run the program again, will the second part of the output look the same? (More than just yes or no)

       

       

       

   8. Explain briefly how this program manages to get the final output that it does (the second part of the output that is not shown).