1. 數字系統轉換

# 負數進制轉換規則

• 做除法扣掉餘數再除 (負數整除)

• 如果餘數是負數，加上這個基數使他為正

private void button1_Click(object sender, EventArgs e)
{
    int num = int.Parse(textBox1.Text);
    int basee = int.Parse(textBox2.Text);
    string res = "";
    while (num != 0)
    {
        int r = num % basee;
        if (r < 0) r += Math.Abs(basee);
        string k;
        if (r < 10) k = r.ToString();
        else k = ((char)('A' + r - 10)).ToString();

        res = k + " " + res;

        num = (num - r) / basee;
    }
    textBox3.Text = res;
}