Nerd Paradise : Coding Interview 2: Get a Random Object from a Stream

Nerd Paradise : Coding Interview 2: Get a Random Object from a Stream
Suppose you have a stream object. This stream object ONLY has two methods. They are:

• HasNext() - returns a boolean if there's more items in the stream
• GetNext() - returns the next item in the stream

Given a stream such as this one, return a random object from it. No, the stream cannot be reset.

function get_random_object(stream):
    size = 1
    object = stream.GetNext()
    while stream.HasNext():
        next = stream.GetNext()

        // generate a random number from 1 to size + 1, inclusive
        if random(1, size + 1) == 1: 
            object = next
        size = size + 1
    return object
Read full article from Nerd Paradise : Coding Interview 2: Get a Random Object from a Stream