菲波那切数列

function fiboAdd(len){
  var res = []
  for(var i = 0; i < len; i++){
    if( i === 0 || i === 1){
      res.push(1)
      }else {
        res.push((res[i-1]+res[i-2]))
      } 
    }
    
  }
  return res
}

function fibonacci (n) {
  if (n==1 || n==2) {
    return 1
  }
  return fibonacci(n-1)+fibonacci(n-2)
}
console.log(fibonacci(3))


const Fib = (n, prev = 1, next = 1) => {
  if (n < 2) {
    return next
  }
  return Fib(n - 1, next, prev + next)
}
console.log(Fib(3))