Hashing is an very interesting topic in competitive programming.Using memory we can efficient our program and that's called Hashing. We are talking about string processing using Hashing. Hash Function : The concept of number system is used for hash function. Suppose, you are given 5, 2 ,5, 2 and asked to make it 5252. You can easily do it. 0 * 10 + 5 = 5 H[1] = 5 1 * 10 + 2 = 52 H[2] = 52 ...