computefibonacci.java

大学java作业源程序

package problem_5;
//ComputeFibonacci.java
import java.io.*;

public class ComputeFibonacci {
	public static void main(String[] args){
		try{
			BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
			System.out.print("Serial number = ");
			Integer n = Integer.valueOf(br.readLine());		//读入待求斐波那契数列项序号，首项序号为1
			if(n.compareTo(0) <= 0)
				System.out.println("Invalid input");		//无效序号输入
			else
				System.out.println("F[" + n.intValue() + "] = " + calculateFibonacci(n.intValue()));
		}
		catch(IOException e){
			System.out.println(e);
		}
	}

	//计算并返回斐波那契数列第n项值
	public static int calculateFibonacci(int n){
		if(n == 1) 
			return 0;
		else if(n == 2)
			return 1;
		else 
			return calculateFibonacci(n - 1) + calculateFibonacci(n - 2);
	}
}