Check out topcoder (http://www.topcoder.com/). They have competitions (good for the motivation thing) in three different difficulty levels. The competitions are for designing algorithms and it can be...

You could add another method to check if the number is in the array first. Then only search for it if it is there. Then you don't have to worry about returning "null", or just return 0 since it...

What exactly do you mean by "online practice"? But check out this thread: C / C++ FAQ's and Practice problems (http://www.daniweb.com/forums/thread67837.html). Yes, thats the C++ forum, but most of...