题解 | 牛牛学数列5

package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)
	f := make([]int, 2)
	f[0] = 1
	f[1] = 1
	if n <= 2 {
		fmt.Print(1)
	} else {
		for i := 3; i <= n; i++ {
			f[0], f[1] = f[1], f[1]+f[0]
		}
		fmt.Print(f[1])
	}
}