SWITCH练习（一年第几天的判断）

using system;
namespace program
{
    class program1
    {
        static void main(string[] args)
        {
            program1 fenshu = new program1();
            fenshu.panduan();
            program1 tian = new program1();
            tian.tianshu();
        }
        /// <summary>
        /// 计算一年中的第几天
        /// </summary>
        void tianshu()
        {
            console.write("请输入年份=");
            int a = convert.toint32(console.readline());
            console.write("请输入月份=");
            int b = convert.toint32(console.readline());
            console.write("请输入日=");
            int c = convert.toint32(console.readline());
            int total = 365;
            if ((total % 4 == 0 && total % 100 != 0) || (total % 400 == 0))//是否闰年的判断
            {
                total = 366;
            }
            switch (b)
            {
                case 1: total -= 31; goto case 2;
                case 2:
                    if ((total % 4 == 0 && total % 100 != 0) || (total % 400 == 0))//闰年二月份有29天                    
                        total -= 29;    //一层可以不使用块                
                    else                    
                        total -= 28;                    
                    goto case 3;
                case 3: total -= 31; goto case 4;
                case 4: total -= 30; goto case 5;
                case 5: total -= 31; goto case 6;
                case 6: total -= 30; goto case 7;
                case 7: total -= 31; goto case 8;
                case 8: total -= 31; goto case 9;
                case 9: total -= 30; goto case 10;
                case 10: total -= 31; goto case 11;
                case 11: total -= 30; goto case 12;
                case 12: total -= 31; goto default;
                default: total += c; break;
            }
            console.writeline("{0}年{1}月{2}日是一年的第{3}天", a, b, c, total);
        }
        /// <summary>
        /// 练习switch
        /// </summary>
        void panduan()
        {
            console.write("请输入学生等级的值=");
            string a = console.readline();
            switch (a)
            {
                case "a": console.writeline("85-100"); break;
                case "b": console.writeline("70-84  "); break;
                case "c": console.writeline("60-69"); break;
                case "d": console.writeline("不及格"); break;
                default: console.writeline("输入有误"); break;
            }
        }
    }
}