import java.util.Scanner; public class Main{ public static void main(String []args){ Scanner sc = new Scanner(System.in); int n = sc.nextInt(); System.out.printf("%d",fib(n)); } public static int fib(int n){ if(n == 1 || n == 2){ return 1; }else{ int a = 1; int b = 1; int c = 0; for(int i = 1; i <= n - 2; i++){ c = a + b; a = b; b = c; } return c; } } }这题我是定义一个方法写的,首先要知道斐波那契数列是啥,就是1 1 2 3 5,就是 a = 1 , b = 2, c = a + b, a = b, b = c ......这样循环就是。