i'm reading cormen's algorithms book (3rd edition), hash functions. the division method is clear (key % m), but there's something i don't understand in multiplication method (page 263-264). the example is on page 264.

here is a reference http://lcm.csa.iisc.ernet.in/dsa/node44.html

the formula is: r1 * 2^w + r0
on the example they get: r1=76300, r0=17612864

i understand how the calculations are...

i'm implementing virtual memory page model in c++. my virtual memory is larger than the physical memory. i've done the allocation part but i can't picture how to do the freeing part. what does actually happen when, for example 20 bytes are deleted (pages are 4 kbyte)? i know that in page table entries there is a present flag for page but here i still have the page, and only 20 bytes of it are deleted? and how do page table entries change? thanks...

i'm learning algorithm analysis, about the different notations, and in class we wrote an example:

f(n) = 1/2*n^2 + 3n,

and wrote it using O-notation, Ω-notation and Θ-notation:

T(n) = Ω(n)
T(n) = O(n^2)
T(n) = Θ(n^2)

now i'm reading the book, where it says f(n) = Θ(g(n)) is true if and only if both f(n) = O(g(n)) and f(n) = Ω(g(n)) are correct....