Solve it as a recurrance relation, i.e. find theclosed form formula and determine if it is Theta(nlogn)
T(n) = 3T(n/3) + dn
Answer
Solving given recurrence relation:
T(n)=3T(n/3)+dn
=3*3T(n/9)+dn+dn
=3*3*3T(n/27)+dn+dn+dn
=…. …. ….
=…. …. ….
=3log3n+dn+dn+dn….+dn (log3ntimes)
=n+log3n*dn
.
Above solution is also ,
Because, log n=(3/2)log3n.
So, nlog3n<=n(1/2)log n, so nlog3n=O(nlog n)
similarly, nlog3n>=n*2log n, so,
Hence, .
Θ(n log:”) (n log n n log, n-Ω( n log n ) n log, n-Θ (n log n )