# 第 1 題 - I (*** 10/15 已說明 ***)
public class Main
{
    public static void main(String args[])
    {
        int m = 3;
    	int n = 2;
        for (int i = 0; i < m * n; i++)    // 執行 i = 0 ~ (m * n - 1) 次
        {
            System.out.print("A");    // 共執行 m * n 次
        }
    }
}



# 第 1 題 - II (*** 10/15 已說明 ***)
public class Main
{
    public static void main(String args[])
    {
        int m = 3;
    	int n = 2;
        for (int j = 1; j <= m; j++)    // 執行 m 次
        {
            for (int k = 1; k < n; k++)    // 執行 n - 1 次
            {
                System.out.print("B");    // 共執行 m * (n - 1) 次
            }
        }
    }
}



# 第 10 題
// 0 2 0 2 0 2 0 要由 k = 0, 2, 3, 5, 6, 8, 9 來產生
public class Main
{
    public static void main(String args[])
    {
        int k = 0;
        while (k < 10)
        {
            System.out.print((k % 3) + " ");
            if ((k % 3) == 0)    // 產生 k = 0, 2, 3, 5, 6, 8, 9
                k = k + 2;
            else
                k++;
        }
    }
}



# 第 11 題
// 和 = ((首項 + 末項）* 項數) / 2 = ((1 + 101) * 51) / 2 = 2601
// 項數 = ((末項 - 首項) / 公差) + 1 = ((101 - 1) / 2) + 1 = 51
public class Main
{
    public static void main(String args[])
    {
        int r = 0;
        int sum = 0;
        
        while (r <= 101)
        {
            if (r % 2 == 1)
            {
                sum += r;
            }
            r++;
        }
        System.out.println(sum);
    }
}



# 第 12 題
public class Main
{
    public static void main(String args[])
    {
        int x = 1;     
        while (x < 0)
        {
            if (x % 2 == 0)
            {
                System.out.print(x + "  ");
            }
            x = x + 2;
        }
    }
}



# 第 13 題 (*** 10/15 已說明 ***)
public class Main
{
    public static void main(String args[])
    {
        for (int outer = 0; outer < 3; outer++)
        {
            for (int inner = outer; inner < 3; inner++)
            {
                System.out.print(outer + "" + inner + "_");
            }
        }
    }
}



# 第 14 題 - I (*** 10/15 已說明 ***)
public class Main
{
    public static void main(String args[])
    {
        int x = 1;
        while (x < 6)
        {
            System.out.print(x + " ");
            x = x + 2;
        }
    }
}



# 第 14 題 - II (*** 10/15 已說明 ***)
public class Main
{
    public static void main(String args[])
    {
        int x = 1;
        while (x < 7)
        {
            System.out.print(x + " ");
            x = x + 2;
        }
    }
}



# 第 15 題 (*** 10/15 已說明 ***)
public class Main
{
    public static void main(String args[])
    {
        int val = 48;
        int div = 6;
        while ((val % 2 == 0) && div > 0)
        {
            if (val % div == 0)
            {
                System.out.print(val + " ");
            }
            val /= 2;
            div--;
        }
    }
}



# 第 16 題
public class Main
{
    public static void main(String args[])
    {
        String new_text = mystery("computer");
        System.out.println(new_text);
    }
    
    public static String mystery(String input)
    {
        String output = "";
        for (int k = 1; k < input.length(); k = k + 2)
        {
            output += input.substring(k, k + 1);
        }
        return output;
    }
}



# 第 17 題
public class Main
{
    public static void main(String args[])
    {
        int start = 4;
        int end = 5;
        boolean keepGoing = true;
        if (start < end && keepGoing)
        {
            if (end > 0)
            {
                start += 2;
                end++;
            }
            else
            {
                end += 3;
            }
        }
        if (start < end)
        {
            if (end == 0)
            {
                end += 2;
                start++;
            }
            else
            {
                end += 4;
            }
        }
        System.out.println(end);
    }
}



# 第 18 題 (*** 10/15 已說明 ***)
public class Main
{
    public static void main(String args[])
    {
        for (int j = 1; j <= 5; j++)
        {
            for (int k = 5; k >= j; k--)
            { 
                System.out.print(j + "  ");
            }
            System.out.println();
        }
    }
}



# 第 22 題
import java.util.Scanner;

public class Main
{
    public static void main(String args[])
    {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Input a number: ");
        int num = scanner.nextInt();

        if (num > 0)
        {
            if (num % 2 == 0)
            { 
                System.out.println("A");
            }
            else
            {
                System.out.println("B");
            }
        }
    }
}



# 第 25 題
public class Main
{
    public static void main(String args[])
    {
        int x = 7;
        int y = 3;

        if ((x < 10)  && (y < 0))
            System.out.println("Value is: " + x * y);
        else
            System.out.println("Value is: " + x / y);
    }
}



# 第 27 題
public class Main
{
    public static void main(String args[])
    {
        String new_str = abMethod("sing the song", "ng");
        System.out.println(new_str);
    }
    
    public static String abMethod(String a, String b)
    {
        int x = a.indexOf(b);
        while (x >= 0)
        {
            a = a.substring(0, x) + a.substring(x + b.length());
            x = a.indexOf(b);
        }
        return a;
    }
}



# 第 30 題
public class Main
{
    public static void main(String args[])
    {
        int num1 = 0;
        int num2 = 3;

        while ((num2 != 0) && ((num1 / num2) >= 0))
        {
            num1 = num1 + 2;
            num2 = num2 - 1;
        }
        System.out.println("num1 = " + num1);
        System.out.println("num2 = " + num2);
    }
}