Algorithm to check whether one set is a proper set from another set

Question

Write an algorithm to check whether a set A is proper set from B or not. (Hint: proper set is that set A is subset from B but they should not be equal, the result should be either True or False, if true that means A is proper set else it is not proper set)

Answer 1

Is Java's collection framework allowed? :)

public boolean properSet(Set<?> a, Set<?> b) {
    return !a.equals(b) && b.containsAll(a);
}

Answer 2

In Python:

A<B

eg:

>>> set("abcd")<set("abcde")
True
>>> set("abcd")<set("abcd")
False
>>> set("abcd")<set("abc")
False

Answer 3

In high level pseudo-code:

• If set A contains the same number of elements as set B, the result is false.
• Look at each element in set A. If it is not in set B, the result is false.
• Otherwise, the result is true.