求兩數奇數和

已知a、b兩正整數，b大於或等於a，求兩數間的奇數和

例：
a=2、b=6
out=8

a=3、b=6
out=8

a=7、b=7
out=7

a=4、b=4
out=0

import java.util.Scanner;
 
public class Demo {
 
    public static void main(String[] args) {
 
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
 
        if(a%2==0)
        {
            a++;
        }
 
        if(b%2==0)
        {
            b--;
        }
 
        int n = (b-a)/2+1;
        System.out.println((a+b)*n/2);
 
    }
}

迴圈解法：

import java.util.Scanner;
 
public class Demo {
 
    public static void main(String[] args) {
 
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
 
        if (a % 2 == 0) {
            a++;
        }
 
        if (b % 2 == 0) {
            b--;
        }
 
        int total=0;
        for (int i = a; i <= b; i += 2) {
            total +=i;
        }
 
        System.out.println(total);
    }
}