java输入N为偶数,求1/2+1/4+......1/n.n为奇数,求1/1+1/3.....1/n

import javax.swing.JOptionPane;
import java.text.DecimalFormat;

public class Test_baidu5 {
public static void main(String args[]) {
int n = 0;
double number = 0;

String input, output;

input = JOptionPane.showInputDialog("键入数字n");

try {
n = Integer.parseInt(input);
} catch (Exception e) {
e.printStackTrace();
System.out.println("输入的字符非数字");
}
if (n % 2 == 0) {
for (int i = 2; i <= n / 2 + 2; i = i + 2) {
number = number + 1.0 / i;
}
} else {
for (int i = 1; i < n / 2 + 4; i = i + 2) {
number = number + 1.0 / i;
}
}
output = "所得值为：" + number;
JOptionPane.showMessageDialog(null, output, "相加总和",
JOptionPane.INFORMATION_MESSAGE);
System.exit(0);
}
}

分两个if判断，再用for循环控制就可以了