Hashing is a technique in Competitive Programming which is mostly used with string. In many cases, using hash can relieve you from doing other complex data structures or complicated dynamic programming optimization. A drawback of hashing is that: you are not completely sure that your solution will work on all cases. If you are really really unlucky, your solution may fail one test-case and receive Wrong Answer. But the chance of failing is very low, and you can even lower that chance by using multiple hashes. So, in the scope of a programming contest, hashing is acceptable and can give … Continue reading Introduction to Hashing