CS3: PROGRAMMING PATTERNS

		         EXAM #1

name: first ________________   last _____________________

The number of points for each question is given in square brackets.


1. [10] Name and differentiate the following two constructs:

         for(auto e: myContainer)   and    for(auto &e: myContainer)

   Explain the situation where one construct is preferred to the
   other. Give an example usage.


2. [10] Explain the differences between shallow copy and deep
   copy. Explain the kind of classes where the two copies
   differ. State the language constructs that eliminate problems that
   this difference creates.


3. [10] Define templates and explain their purpose. Differentiate
   standalone function and class templates. Give an example of a class
   template and a function template.


4. [15] Differentiate sequential, associative and unordered STL
   containers.  Explain the need for specialized list algorithms,
   i.e. why it is not sufficient to use general purpose STL
   algorithms. Give an example use of one such algorithm.


5. [10] Define container adapters that we studied. Explain why
   container adapters more suitable for some tasks than regular
   sequential container. State one container adapter and describe
   operations that are available for this adapter.


6. [15] Define iterator invalidation. Explain the reason for this
   invalidation. Point out the problem in the following code
   and correct it.

     vector <int> v = {10, 20, 30, 40, 50, 60};

     int i;
     cout << "Enter number to remove from vector: "; cin >> i;

     for(auto it = v.begin(); it != v.end(); ++it)
        if(*it == i) v.erase(it);


7. [15] Define a callback. Name three kinds of callbacks that we
   studied. Simplify the following code using a lambda-expression.

   bool notZero(int e){return e!=0;}
   ...
   auto it=find_if(vect.begin(), vect.end(), notZero);


8. [15] Explain why modifying STL algorithms such as remove() and
   unique() do not actually eliminate the unsuitable elements from the
   container. Describe remove-erase idiom. Assuming that "v" is a
   vector of integers. Explain what the below code does.

   v.erase(remove_if(v.begin(), v.end(), [](int i){return i > 5;}), v.end());