题解 | #斐波那契数列#

public class Solution {
    public int Fibonacci(int n) {
         if (n < 1) return n;
        int[] fib = new int[3];
        fib[0] = 0;
        fib[1] = 1;
        for (int i = 2; i <= n; i++) {
            fib[i % 3] = fib[(i - 1) % 3] + fib[(i - 2) % 3];
        }
        return fib[n % 3];
    }
}