java基础50道经典练习题 例39
【程序39】
题目:编写一个函数,输入n为偶数时,调用函数
求1/2+1/4+...+1/n,当输入n为奇数时,调用函数
1/1+1/3+...+1/n(利用指针函数)
import java.util.Scanner;
public class Test09 {
【程序39】
题目:编写一个函数,输入n为偶数时,调用函数
求1/2+1/4+...+1/n,当输入n为奇数时,调用函数
1/1+1/3+...+1/n(利用指针函数)
*/
public static void main(String[] args) {
System.out.print("请输入一个数: ");
Scanner sc = new Scanner(System.in);
int number = sc.nextInt();
if(0 == number%2) {
System.out.println("="+evenSum(number));
}else {
System.out.println("="+oddSum(number));
}
}
private static float oddSum(int number) {
float odd_sum = 0;
if(1 == number)
odd_sum = (1.0f/1);
else
odd_sum = (oddSum(number-2)+(1.0f/number));
System.out.print("1/"+number+"+");
return odd_sum;
}
private static float evenSum(int number) {
float even_sum = 0;
if(2 == number)
even_sum = (1.0f/2);
else
even_sum = (evenSum(number-2)+(1.0f/number));
System.out.print("1/"+number+"+");
return even_sum;
}
}