Question

java编写一个函数，输入n为偶数时调用函数1/2+1/4+...+1/n ，当输入n为奇数时调用

java编写一个函数，输入n为偶数时调用函数1/2+1/4+...+1/n ，当输入n为奇数时调用函数1/1+1/3+...+1/n

Answer 1

public static void main(String[] args) {
// java编写一个函数，输入n为偶数时调用函数1/2+1/4+...+1/n ，当输入n为奇数时调用函数1/1+1/3+...+1/n
System.out.println(test(3));
}

public static double test(int n) {
double sum = 0;
if (n % 2 == 0) {
for (int i = 2; i <= n; i += 2) {
sum += 1.0 / i;
}
} else {
for (int i = 1; i <= n; i += 2) {
sum += 1.0 / i;
}

}
return sum;
}

Answer 2

static float test(int num){
float result=0;
if(num<=0) return result;
do{
result += 1.f/num;
num = num-2;
}while(num>0);
return result;
}

Answer 3

package Demo8;

import java.util.Scanner;

//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
public class Test4 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("请输入一个数：");
int i = sc.nextInt();
if (i % 2 == 0) {
System.out.println(Oshow(i));
} else {
System.out.println(Jshow(i));
}
}

private static double Oshow(int n) {
double sum = 0;
while (n > 0) {
sum +=(double) 1 / n ;
n-=2;
}
return sum;
}

private static double Jshow(int n) {
double sum = 0;
while (n > 0) {
sum +=(double) 1 / n ;
n-=2;
}
return sum;
}
}