Hash table is a data structure using a small amount of space to store the values which in a large space. The access time is constant.
G Hash function x % 2 h 0 1 2 3 4 5 6 7 l 0 1 h:0->l:0 h:1->l:1 h:2->l:0 h:3->l:1 h:4->l:0 h:5->l:1 h:6->l:0 h:7->l:1