The master method works well on problems like $ T(n)=kT(an)+cn$ , but it does not handle problems like $ $ T(n)=n^{\frac{1}{3}}T(n^{\frac{2}{3}})+n^2$ $ With the number of branches for each partition is a function of $ n$ . I wonder if there’s a good solution to this kind of problems, I have no idea how to solve this, any help is appreciated!