# 2648. Generate Fibonacci Sequence

###### tags: `leetcode 30 days js challenge` `Easy`

[2648. Generate Fibonacci Sequence](https://leetcode.com/problems/generate-fibonacci-sequence/)

### 題目描述

Write a generator function that returns a generator object which yields the **fibonacci sequence**.

The fibonacci sequence is defined by the relation `Xn = Xn-1 + Xn-2`.

The first few numbers of the series are `0, 1, 1, 2, 3, 5, 8, 13`.

### 範例

**Example 1:**

Input: callCount = 5
Output: [0,1,1,2,3]
Explanation:
const gen = fibGenerator();
gen.next().value; // 0
gen.next().value; // 1
gen.next().value; // 1
gen.next().value; // 2
gen.next().value; // 3

**Example 2:**

Input: callCount = 0
Output: []
Explanation: gen.next() is never called so nothing is outputted

**Constraints**:

- `0 <= callCount <= 50`

### 解答

#### TypeScript

function* fibGenerator(): Generator<number, any, number> {
  let prev = 0;
  let curr = 1;

  while (true) {
    yield prev;

    let next = prev + curr;
    prev = curr;
    curr = next;
  }
}

> [name=Sheep][time=Fri, June 2, 2023]

### Reference

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