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The.Algorithm.Design.Manual.Springer-Verlag.1998

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Lecture 3 - recurrence relations<br />

Reading from the equation, a=4, b=2, and .<br />

Is ?<br />

Yes, for , so case 3 might apply.<br />

Is ?<br />

Yes, for , so there exists a c < 1 to satisfy the regularity condition, so case 3 applies and<br />

.<br />

Listen To Part 3-11<br />

Consider T(n) = a T(n/b) + f(n).<br />

Say f(n)=0, ie. T(n) = a T(n/b).<br />

Why should the Master <strong>The</strong>orem be true?<br />

Suppose f(n) is small enough<br />

<strong>The</strong>n we have a recursion tree where the only contribution is at the leaves.<br />

<strong>The</strong>re will be levels, with leaves at level l.<br />

so long as f(n) is small enough that it is dwarfed by this, we have case 1 of the Master <strong>The</strong>orem!<br />

Listen To Part 3-12<br />

file:///E|/LEC/LECTUR17/NODE3.HTM (7 of 10) [19/1/2003 1:34:27]

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