freeCodeCamp/curriculum/challenges/chinese/08-coding-interview-prep/project-euler/problem-197-investigating-the-behaviour-of-a-recursively-defined-sequence.chinese.md

id	challengeType	title	videoUrl	localeTitle
5900f4311000cf542c50ff44	5	Problem 197: Investigating the behaviour of a recursively defined sequence		问题197：研究递归定义的序列的行为

Description

给定函数f（x）=⌊230.403243784-x2⌋×10-9（⌊⌊是floor函数），序列un由u0 = -1和un + 1 = f（un）定义。

找到n + 1012的un + un + 1.在小数点后面给出9位数的答案。

Instructions

Tests

tests:
  - text: <code>euler197()</code>应该返回1.710637717。
    testString: 'assert.strictEqual(euler197(), 1.710637717, "<code>euler197()</code> should return 1.710637717.");'

Challenge Seed

function euler197() {
  // Good luck!
  return true;
}

euler197();

Solution

// solution required