Q. What do you understand by the term by hash clash? Explain in detail any one method to resolve the hash collisions.                                                                                                   

Ans:

Hashing is not a perfect technique. The collision occurs seldom when the two different key hash into the same hash value and are also assigned to the same array element by mistake. Programmers have come up with number of techniques for dealing with this problem. An ordinary way to deal with a collision is to create a linked list of entries that have their hash value same. For example, let the key of each entry hashes to the same hash value and this process result in both being assigned to the same array element of the particular hashtable.

Because the two entries cannot be assigned the same array element, the programmer makes a linked list. The first user-explained structure is assigned to the pointer in the array element. The second isn't assigned to any of the array element and is instead linked to the first user-defined structure, therefore forming a linked list.

For example: in the below table of the size 7

42, 56 both are mapped to index 0 as 42%7=0 and 56%7=0.

25, 42, 96, 101, 102, 162, 197 can be mapped as shown below: