What circumstances must be satisfied for an algorithm that ordinarily recursively calls itself to no longer do so?

C programing Draw the recursion tree to find out the value of f(5)int f(int n){int ans;int i;if(n<3)return n;ans = f(n/2);for(i=0; i<n; i++)ans += f(i);return ans;}

Fibonacci sequence is given by the recursive relation:F(0) = 1 and F(1) = 1F(n) = F(n-1) + F(n-2)Ultimately, as discussed in lecture 6, Slide 23, it can be shown that: F(n) =1/√5 ((1+√5)/2)n - 1/√5((1-√5)/2)n The number (1+√5)/2 = 1.618 is called the Golden Ratio Clearly F(n) = O(2n).Write a recursive program like the one described in Lecture 5, Slide 32.Then, perform a numeric asymtotic analysis and try to determine a more precise asymptotic estimate of time needed to calculate F(n) (e.g., use a time function).Esentially, try to estimate/infer the tight bound, (f(n)). More details on Big O and in Lecture 5b.Upload both the program (upload your exact cpp, java, py file - source files) and a pdf file analyzing the output of your program.

What is the difference between a recursive and an iterative algorithm?