Nth Fibonacci number
Return the nth number in the Fibonacci sequence, counting from zero.
- fib(0) is 0 and fib(1) is 1; every later term is the sum of the two before it.
- n stays within 0..45.
fibonacci(n: int) → int
Go needs a compiler and Drill does not host one yet, so this page is the reference rather than an exercise: the problem, worked examples, and the solution in full. To type it out, the same problem runs in Python.
Where you start
func fibonacci(n int) int {
}Worked examples
| Call | Result |
|---|---|
fibonacci(0) | 0 |
fibonacci(1) | 1 |
fibonacci(2) | 1 |
fibonacci(10) | 55 |
Hint
Keep two variables and slide them forward. No recursion needed.
Reference solution in Go
func fibonacci(n int) int {
a, b := 0, 1
for i := 0; i < n; i++ {
a, b = b, a+b
}
return a
}