使用递归方式实现

存在大量重复运算

  1. function fibonacci(n) {
  2.   if (n <= 1) {
  3.     return n;
  4.   }
  6.   return fibonacci(n - 1) + fibonacci(n - 2);
  7. }

使用迭代方式

  1. function fibonacci(n) {
  2.   if (n <= 1) {
  3.     return n;
  4.   }
  6.   let first = 0;
  7.   let second = 1;
  9.   for (let i = 0; i < n - 1; i++) {
  10.     second = first + second;
  11.     first = second - first;
  12.   }
  14.   return second;
  15. }