Answer to Quiz 3(a) Tue 4 Sep 2001

1. Consider the statement i = j += k for some ints i, j, and k.

   Write a sequence of instructions that do the same as this
   statement WITHOUT using the operators += and -- :

        k = k-1;
        j = j+k;
        i = j;



2. Analyze the following program :

                                 -------------------------------------
   include<stdio.h>              | steps in | values after each step |
                                 |          |------------------------|
   int main(void)                |   while  |      i     |     p     |
   {                             |===================================|
      int n = 100;               |          |            |           |
      int i = 0, p = 1;          |     0    |      0     |     1     |
                                 |          |            |           |
      while (p < n)              |     1    |      1     |     2     |
      {                          |     2    |      2     |     4     |
         p *= 2;                 |     3    |      3     |     8     |
         i++;                    |     4    |      4     |    16     |
      }                          |     5    |      5     |    32     |
      printf("%d=2^%d", p, i);   |          |            |           |
      return 0;                  -------------------------------------
   }


Complete the table at the right of the program
with values for i and p after each step in the
execution of the while loop.

Then answer the following:

(a) How many times is the while loop executed?     5

(b) What does the program print?                  32=2^5