Charlie likes Alice's picture-password system of the previous exercise, but he has changed the login so that it just shows the user 40 different pictures in random order and they have to indicate which 20 of these are from their set of favorites. Is this an improvement over Alice's system? Why or why not?
What will be an ideal response?
Note that there are two pictures for each choice in the original plan, one on
the left and one on the right. Thus, with 20 pairs, there is a search space of 220, which is
roughly equal to 1 million. If the search space is defined by picking 20 out of 40, then the
size of the search space is the combinatorial function "40 choose 20," which is 40!/(20!)2,
i.e., it is over 137 trillion.
You might also like to view...
Once created a custom function cannot be edited
Indicate whether the statement is true or false
To actually use a returned value, you must provide a(n) ____________________ to store the value or to use the value in an expression.
Fill in the blank(s) with the appropriate word(s).
Consider the following definition of the recursive function mystery.int mystery(int first, int last){ if (first > last) return 0; else if (first == last) return first; else return first + mystery(first + 1, last - 1);}What is the output of the following statement?cout
A. 13 B. 21 C. 40 D. 42
A customer wants a computer for performing a single-threaded task as quickly as possible. Which of thefollowing CPU characteristics is the MOST important?
A. Clock speed B. Hyperthreading C. Fan speed D. Number of cores