题解 | #62.斐波那契数列#

小技巧：[left,right] = [right,left+right]

function Fibonacci(n)
{
  if(n==1 || n==2)
    return 1;
  n = n-2;
  let left=1,right=1;
  while(n--){
    [left,right] = [right,left+right];
  }
  return right;
}

function Fibonacci(n){
  if(n<=2)
    return 1;
  return Fibonacci(n-1) + Fibonacci(n-2);
}