This is a C++ problem. Please give full explanation and code in details. Thanks.

Fibonacci numbers arise in a number of different places and are related to the golden ratio. Fibonacci numbers are defined by fo= 0, fi = 1, and f= f-it fi-2 for i > 1. So, for example, f-f + fo 1 + 0 = 1, and f3= f2 fi Write a program that asks a user to to input an index i, and then computes and prints out the Fibonacci number fi. You can assume the input is a nonnegative integer; you do not need to validate it. [Hint: Although this problem is presented using a series of values fo. fi, f,.., when computing the next Fibonacci number, all you need to keep track of is the previous two Fibonacci numbers.]