Computer Science
posted by gaurav .
The digits 0, 1, and 8 look much the same if rotated 180 degrees on the page (turned
upside down). Also, the digit 6 looks much like a 9, and vice versa, when rotated 180
degrees on the page. A multidigit number may also look like itself when rotated on the
page; for example 9966 and 10801 do, but 999 and 1234 do not.
You are to write a program to count how many numbers from a given interval look like
themselves when rotated 180 degrees on the page. For example, in the interval [1..100]
there are six : 1, 8, 11, 69, 88, and 96.
Your program should take as input two integers, m and n, which define the interval to be
checked, 1 â‰¤ m â‰¤ n â‰¤ 32000. The output from your program is the number of rotatable
numbers in the interval.
You may assume that all input is valid.
Input/output is not from/to files for this question. Keyboard input and screen output is
expected.
Sample Session User input is in italics.
Enter the lower bound of the interval:
1
Enter the upper bound of the interval:
100
The number of rotatable numbers is:
6
I am kind of stuck withe logic... help me please.

Yes .... Quadrature PSK or QPSK has a menu of 4 phases (45, 135, 225 & 315 degrees), where two bits designate each symbol. 8PSK, 16PSK, . . . 256PSK are also in use.