mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-01-11 02:58:13 +08:00
32 lines
853 B
HTML
32 lines
853 B
HTML
|
<p>泰波那契序列 T<sub>n</sub> 定义如下： </p>
|
|||
|
|
|
|||
|
|
<p>T<sub>0</sub> = 0, T<sub>1</sub> = 1, T<sub>2</sub> = 1, 且在 n >= 0 的条件下 T<sub>n+3</sub> = T<sub>n</sub> + T<sub>n+1</sub> + T<sub>n+2</sub></p>
|
|||
|
|
|
|||
|
|
<p>给你整数 <code>n</code>，请返回第 n 个泰波那契数 T<sub>n </sub>的值。</p>
|
|||
|
|
|
|||
|
|
<p> </p>
|
|||
|
|
|
|||
|
|
<p><strong>示例 1：</strong></p>
|
|||
|
|
|
|||
|
|
<pre><strong>输入：</strong>n = 4
|
|||
|
|
<strong>输出：</strong>4
|
|||
|
|
<strong>解释：</strong>
|
|||
|
|
T_3 = 0 + 1 + 1 = 2
|
|||
|
|
T_4 = 1 + 1 + 2 = 4
|
|||
|
|
</pre>
|
|||
|
|
|
|||
|
|
<p><strong>示例 2：</strong></p>
|
|||
|
|
|
|||
|
|
<pre><strong>输入：</strong>n = 25
|
|||
|
|
<strong>输出：</strong>1389537
|
|||
|
|
</pre>
|
|||
|
|
|
|||
|
|
<p> </p>
|
|||
|
|
|
|||
|
|
<p><strong>提示：</strong></p>
|
|||
|
|
|
|||
|
|
<ul>
|
|||
|
|
<li><code>0 <= n <= 37</code></li>
|
|||
|
|
<li>答案保证是一个 32 位整数，即 <code>answer <= 2^31 - 1</code>。</li>
|
|||
|
|
</ul>
|