Show that the solution of is O(lg n).
We saw that the solution of is O(n lg n). Show that the solution of this recurrence is also Ω(n lg n). Conclude that the solution is Θ(n lg n).
Show that by making a different inductive hypothesis, we can overcome the difficulty with the boundary condition T (1) = 1 for the recurrence (4.4) without adjusting the boundary conditions for the inductive proof.
Show that Θ(n lg n) is the solution to the "exact" recurrence (4.2) for merge sort.
Show that the solution to is O(n lg n).
Solve the recurrence  by making a change of variables. Your solution should be asymptotically tight. Do not worry about whether values are integral.
设n = lgn,得到新的递归式
再令S(n) = T(2^n)可以得到
按照前面的方法解这个递归式即可
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