Hash 函数

Hashing

                H(key)= key %M

Linear probe

                Slot = (home+i)%M

                                Homeis index to which the key originally mapped by the hash function

                Slot =(home +i*c)%M

Quadratic probe

                Slot =(home + i^2)%M

Double hashing

                Slot =(home + i*hp(key))%M

                Hp(key)= 1 + key %P

Rehashing

                Enlargethe hash table size and then rebuild the whole hash table.

Separate chaining

                Linked listis used to store the individual keys that map to the same entry.

Hash function:

                Division

                Truncation

                                Key:4873152 = 812 [select digits from specific column]

                Folding

                                Key: 4873152= 48+731+52=831

                HashingStrings

                                Sting‘hashing’ = 104+97+115+104+105+110+103 = 738