different Fibonacci answers

fib-answers.ts

const at = <T,>(arr: T[], index: number) => index < 0 
    ? arr[arr.length + index] 
    : arr[index];

let recursiveFibCount = 0
const rFibonnaci = (num = 1, prevSeq: number[] = [0]): number => {
    if(prevSeq.length === num) {
       return at(prevSeq, -1)
    } 
    if(prevSeq.length === 1) return rFibonnaci(num, [0, 1])
    recursiveFibCount += 1
    return rFibonnaci(num, [...prevSeq, at(prevSeq, -2) + at(prevSeq, -1)]) 
}

let whileLoopFibCount = 0
const wFibonnaci = (num = 1): number => {
    const prevSeq = [0]
    while(prevSeq.length < num){
      whileLoopFibCount += 1
      switch(prevSeq.length){
        case 1:
          prevSeq.push(1)
        default:
          prevSeq.push(at(prevSeq, -2) + at(prevSeq, -1))
      }
    }
    return at(prevSeq, -1)
}

const fib = [0]
let memoizedFibCount = 0
const wFibonnaciMemoized = (num = 1): number => {
    while(fib.length < num){
      memoizedFibCount++
      switch(fib.length){
        case 1:
          fib.push(1)
        default:
          fib.push(at(fib, -2) + at(fib, -1))
      }
    }
    // console.log(fib)
    return at(fib, num - 1)
}

const range = (n: number) => {
    const arr = []
    for(let i = 1; i <= n; i++){
       arr.push(i)
    }
    return arr
}

const nums = range(50)
nums.map(n => rFibonnaci(n))
nums.map(n => wFibonnaci(n))
nums.map(n => wFibonnaciMemoized(n))

console.log({
    whileLoopFibCount,
    recursiveFibCount,
    memoizedFibCount,
})