Data Structures, Algorithms, & Applications in C++
Chapter 3, Exercise 19

(a)
Program A is faster than program B when 1000n < 10n2, that is when n > 100.

(b)
Program A is faster than program B when 2n2 < n3, that is when n > 2.

(c)
Program A is faster than program B when 2n < 100n, that is when n < 10.

(d)
Program A is faster than program B when 1000n log2n < n2, that is when n > 1000 log2n. The switchover point is between 213 and 214.