n-th-tribonacci-number

java

python

python3

mysql

mssql

oraclesql

csharp

javascript

typescript

bash

swift

kotlin

dart

golang

ruby

scala

rust

racket

erlang

elixir

pythondata

postgresql

cangjie

Algorithms

The Tribonacci sequence Tn is defined as follows:&nbsp;

T0 = 0, T1 = 1, T2 = 1, and Tn+3 = Tn + Tn+1 + Tn+2 for n &gt;= 0.

Given <code>n</code>, return the value of Tn.

&nbsp;
Example 1:

<pre>
Input: n = 4
Output: 4
Explanation:
T_3 = 0 + 1 + 1 = 2
T_4 = 1 + 1 + 2 = 4
</pre>

Example 2:

<pre>
Input: n = 25
Output: 1389537
</pre>

&nbsp;
Constraints:

<ul>
	<li><code>0 &lt;= n &lt;= 37</code></li>
	<li>The answer is guaranteed to fit within a 32-bit integer, ie. <code>answer &lt;= 2^31 - 1</code>.</li>
</ul>

tribonacci

N-th Tribonacci Number

Climbing Stairs

climbing-stairs

爬楼梯

Fibonacci Number

fibonacci-number

斐波那契数

Memoization

Math

Dynamic Programming

泰波那契序列&nbsp;Tn&nbsp;定义如下：&nbsp;

T0 = 0, T1 = 1, T2 = 1, 且在 n &gt;= 0&nbsp;的条件下 Tn+3 = Tn + Tn+1 + Tn+2

给你整数&nbsp;<code>n</code>，请返回第 n 个泰波那契数&nbsp;Tn 的值。

&nbsp;

示例 1：

<pre>输入：n = 4
输出：4
解释：
T_3 = 0 + 1 + 1 = 2
T_4 = 1 + 1 + 2 = 4
</pre>

示例 2：

<pre>输入：n = 25
输出：1389537
</pre>

&nbsp;

提示：

<ul>
	<li><code>0 &lt;= n &lt;= 37</code></li>
	<li>答案保证是一个 32 位整数，即&nbsp;<code>answer &lt;= 2^31 - 1</code>。</li>
</ul>