Perfect hashing simply means hashing with no collision.But there is nothing like perfect hashing(no collision).These are just a work around to achieve perfect hashing.Using this we can able to search the large set of records in a constant time i.e O(1) time complexity.To achieve searching in strict O(1) time ,one needs to implement hash table and then search the given record in to hash table using hash function. Here in perfect hashing ,one need to implement two level hash table , first level hash table consist a set of pointers that points to the second level hash table,we must select hash function that first maps the key in to first level hash table,so it simply means there must be collision in first level hash table ,thats why i am saying its just a work around to achieve prefect hashing.We must wisely choose hash function: h(x)=((a*x+b)mod p)mod m x is the key to be map, Here ...