Interview Question 10- I. Fibonacci Sequence [JavaScript]

Write a function and enter n to find the nth term of the Fibonacci sequence. The definition of Fibonacci sequence is as follows:

F(0) = 0, F(1) = 1
F(N) = F(N-1) + F(N-2), where N> 1. The
Fibonacci sequence starts with 0 and 1, and the following The Fibonacci number is obtained by adding the previous two numbers.

The answer needs to be modulo 1e9+7 (1000000007). If the initial result of the calculation is: 1000000008, please return 1.

Example 1:

Input: n = 2
Output: 1
Example 2:

Input: n = 5
Output: 5

Source: LeetCode (LeetCode)
Link: https://leetcode-cn.com/problems/fei-bo-na-qi-shu-lie-lcof
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The idea of ​​this question is relatively simple, the main thing is to pay attention to it, that is, take the surplus, and teach with blood and tears!

Code! ! !

/**
 * @param {number} n
 * @return {number}
 */
var fib = function(n) {
    
    
if(n==0)return 0;
if(n==1) return 1;
let s=0;
let l=1;
for(let i=1;i<n;i++)
    {
    
    
        let t = s
        s = l
        l = (t + l)%1000000007;
    }
    return l;
};