CS253: Software Development with C++

Fall 2019

IQ 15

CS253 IQ 15

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set<int> default second template argument

  1. operator<
  2. less
  3. less<int>
  4. less<int>()
  5. There isn’t one.

C: it must be a type, a comparison functor, not an object.

bind

What’s the easiest way to create a variable pointing to the function beta, which calls the two-argument function alpha, but with the arguments swapped?

  1. bind(beta, alpha, 2, 1);
  2. auto beta = bind(alpha, 2, 1);
  3. auto beta = bind(alpha, _2, _1);
  4. A lambda function would be shorter.
  5. int beta(int a, int b) { return alpha(b,a); }

What is the period of minstd_rand?

  1. 232
  2. 232−1
  3. 231
  4. 231−1
  5. 231−2
  6. I don’t know what “period” means. ☹

The word “period” means how many values it returns before it repeats.
E: x = x * 48271 % 2147483647 // always positive, never zero

Random Numbers

mt19937 is deterministic—given the same seed, it will produce the same sequence of numbers each time.

  1. yes
  2. no
  3. depends on the implementation
  4. mt19937 is not a generator.

A: All generators are deterministic, perhaps except for random_device.

Where is the final exam?

  1. here
  2. someplace else

Here! This very room!

When is the final exam?

  1. Thursday December 19 6:20ᴀᴍ
  2. Thursday December 19 6:20ᴘᴀ
  3. Thursday December 19 6:20ᴍᴘ
  4. Thursday December 19 6:20ᴘᴍ
  5. Thursday December 19 6:20ᴍᴀ
  6. Thursday December 19 6:20ᴀᴘ

Thursday December 19 6:20ᴘᴍ