On a computer, where the non-recursive Dynamic Programming solution to compute the n'th Fibonacci term takes 1 second to find the 40th term, the corresponding recursive solution will take approximately 56 hours to find the same 40th Fibonacci term.
It is because the small innocent-looking recursive solution of Fibonacci takes exponential time, whereas the DP solution takes linear time.
Dynamic programming questions are the most difficult to answer in competitions and interviews. In most coding competitions, a recursive solution will not pass all test cases. This book takes dynamic programming head-on.
