I recommend beginners to try out these some interesting problem which might help them to try out new way to think.. - 2048 Game.
- Two Teams Composing.
- Frog Jump.
- Weird sort.
- Dominated subarray.
- Copying Homework.
- Deadline
Thanks
oracle7 :)

if you are learning bit manipulation or bit masking and come across with a classical problem name called Counting number of set bits then you must give this a try...

Raising Bacteria

Hope you learn and enjoy:)