C ++ algorithm's Fibonacci series, algorithm's Fibonacci Series

C ++ algorithm's Fibonacci series, algorithm's Fibonacci Series

Question: Write a function and input n to obtain the nth entry of the Fibonacci series.

 

Method 1: recursion:

Int fiber 2 (int n) {if (n = 0) return 0; if (n = 1) return 1; return fiber 2 (n-1) + fiber 2 (n-2 );}

Disadvantage: If n is large, the recursion degree is deep.

 

Method 2:

Int fib (int n) {int result [2] = {0, 1}; if (n <2) return result [n]; int fiber one = 0; int fiber 2 = 1; int fiber n = 0; int I = 0; for (I = 2; I <= n; I ++) {fiber = fiber one + fiber two; fiber one = fiber two; maid;} return maid ;}

This avoids infinite recursion. The complexity of a cycle is O (n );