AlgoDaily - Fibonacci Sequence

Fibonacci Sequence (Medium)

Good afternoon! Here's our prompt for today.

You may see this problem at Indeed, Apple, Zillow, Splunk, Snowflake, Cockroach Labs, and Digitate.

Implement a function that returns the Fibonnaci number for a given integer input. In a Fibonacci sequence, each number is the sum of the two preceding ones.

The simplest is the series: 1, 1, 2, 3, 5, 8, etc.

This is because:

SNIPPET

1fibonacci(0) = 0
2fibonacci(1) = 1
3fibonacci(2) = 1
4fibonacci(3) = 1 + 1 = 2
5fibonacci(4) = 1 + 2 = 3
6fibonacci(5) = 2 + 3 = 5

So if we were to invoke fibonacci(5), we'd want to return 5 (because the second to last number was 2 + last number was 3).

Constraints

The value of n will always be a non negative integer and <=40
The answer is guaranteed to fit in the integer data type
Expected time and space complexity are both O(n)

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​
 
var assert = require('assert');
​
/*
 * @param {number} n The Fibonacci number to get.
 * @returns {number} The nth Fibonacci number
 */
​
function fibonacci(num) {
  // fill this in
  return num;
}
​
try {
  assert.equal(fibonacci(1), 1);
​
  console.log('PASSED: ' + '`fibonacci(1)` should return `1`');
} catch (err) {
  console.log(err);
}
​
try {
  assert.equal(fibonacci(17), 1597);
​
  console.log('PASSED: ' + '`fibonacci(17)` should return `1597`');
} catch (err) {
  console.log(err);
}

OUTPUT

Results will appear here.