Solution
The correct answer is : option 2.
Key Points
Explanation of the Recurrence Relation Solution
Given the recurrence relation: T(n) = T(2n/3) + 1
To solve this, we will use the Master Theorem for divide-and-conquer recurrences of the form:
T(n) = aT(n/b) + f(n)
In our case, a = 1, b = 3/2, and f(n) = 1.
Using the Master Theorem, we compare f(n) with n^log_b(a):
a = 1
b = 3/2
log_b(a) = log(1) / log(3/2) = 0
f(n) = 1
Since f(n) = 1 is Θ(1), it matches the case where f(n) = Θ(n^c) with c = 0. This corresponds to case 2 of the Master Theorem, where f(n) is polynomially smaller than n^log_b(a).
Therefore, the solution to the recurrence is:
T(n) = Θ(log n)
Thus, the correct answer is option 2.