Modulo Arithmetic

• Sometimes the numbers just add to be too large:

  • Suppose you are hashing arbitrarily long integers. The addition of 999999999999999999999999999999 is 270 and you might only have space for 100 items in the array.

• You can simply take the modulo of the resulting number as the address 270%100 = 70. (This is rather asymmetric though)

• It is generally wise when using modulo to choose a table size that is a prime number. This increases the chance of uniform distribution over the entire space of the table.