package math;

public class Fibonacci {
 public static void main(String[] args) {
 int n = 10; // 要生成的斐波那契数列的长度
 System.out.println("Fibonacci Series up to " + n + " terms:");
 for (int i = 0; i < n; i++) {
 System.out.print(fibonacci(i) + " ");
 }
 }


 public static void main2() {
 int n = 10; // 要计算的斐波那契数列的长度
 System.out.println("斐波那契数列前 " + n + " 个数为:");
 for (int i = 0; i < n; i++) {
 System.out.print(fibonacci2(i) + " ");
 }
 }

 /**
 * 斐波那契数列 递归实现
 *
 * @param n
 * @return
 */
 public static int fibonacci(int n) {
 if (n <= 1) {
 return n;
 } else {
 return fibonacci(n - 1) + fibonacci(n - 2);
 }
 }

 /**
 * 迭代法实现斐波那契数列
 *
 * @param n
 * @return
 */
 public static int fibonacci2(int n) {
 if (n <= 1) {
 return n;
 }
 int fib = 0;
 int prev1 = 0;
 int prev2 = 1;
 for (int i = 2; i <= n; i++) {
 fib = prev1 + prev2;
 prev1 = prev2;
 prev2 = fib;
 }
 return fib;
 }
}