Define a function `count_words` that, given an input string, return a hash whose keys are words in the string and whose values are the number of times each word appears: "to be or not to be" # => {"to"=> 2, "be"=> 2, "or"=> 1, "not"=> 1} your solution shouldn't use for-loops, but iterators like `each` are permitted. as before, nonwords and case should be ignored. a word is defined as a string of characters between word boundaries.

Effective character encoding requires standardized code. compatible browsers. common languages. identical operating systems.

Use a physical stopwatch to record the length of time it takes to run the program. calculate the difference obtained by calls to the method system. currenttimemillis() just before the start of the algorithm and just after the end of the algorithm. calculate the difference obtained by calls to the method system. currenttimemillis() at the start of the program and at the end of the program so that the elapsed time includes the display of the result. use the value returned by the method system. currenttimemillis() just after the end of the algorithm as the elapsed time.

The idea that, for each pair of devices v and w, there’s a strict dichotomy between being “in range” or “out of range” is a simplified abstraction. more accurately, there’s a power decay function f (·) that specifies, for a pair of devices at distance δ, the signal strength f(δ) that they’ll be able to achieve on their wireless connection. (we’ll assume that f (δ) decreases with increasing δ.) we might want to build this into our notion of back-up sets as follows: among the k devices in the back-up set of v, there should be at least one that can be reached with very high signal strength, at least one other that can be reached with moderately high signal strength, and so forth. more concretely, we have values p1 ≥ p2 ≥ . . ≥ pk, so that if the back-up set for v consists of devices at distances d1≤d2≤≤dk, thenweshouldhavef(dj)≥pj foreachj. give an algorithm that determines whether it is possible to choose a back-up set for each device subject to this more detailed condition, still requiring that no device should appear in the back-up set of more than b other devices. again, the algorithm should output the back-up sets themselves, provided they can be found.\