The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1. That is,
F(0) = 0, F(1) = 1 F(n) = F(n - 1) + F(n - 2), for n > 1. Given n, calculate F(n).
Example 1:
Input: n = 2
Output: 1
Explanation: F(2) = F(1) + F(0) = 1 + 0 = 1.
Example 2:
Input: n = 3
Output: 2
Explanation: F(3) = F(2) + F(1) = 1 + 1 = 2.
Example 3:
Input: n = 4
Output: 3
Explanation: F(4) = F(3) + F(2) = 2 + 1 = 3.
Constraints:
0 <= n <= 30
斐波那契数列，最基础的定义
1. F(0) == 0
2. F(1) == 1
3. F(n) == F(n-1)+F(n-2)
func fib(n int) int {
if n <= 1 {
return n
}
fibRes := make([]int, n+1)
fibRes[0],fibRes[1] = 0, 1
for i := 2; i <= n; i++ {
fibRes[i] = fibRes[i-1] + fibRes[i-2]
}
return fibRes[n]
}