using System;
namespace Lesson10
{
    class program
    {
        static void Main(string[] args)
        {
            #region 年龄
            int myAge = 18;
            myAge += 10;
            Console.WriteLine("十年后我的年龄是：" + myAge);
            #endregion


            #region 圆的面积
            const float PI = 3.1415926f;
            int radius = 5;
            float area = PI * radius * radius;
            float circumference = 2f * PI * radius;
            Console.WriteLine("半径为" + radius + "的圆的面积是：" + area + "周长是:" + circumference);
            #endregion

            #region 计算成绩
            int score1 = 80;
            int score2 = 90;
            int score3 = 92;
            int totalScore = score1 + score2 + score3;
            float avgScore = totalScore / 3.0f;
            Console.WriteLine("你的总成绩为:" + totalScore);
            Console.WriteLine("你的平均分为:" + avgScore);
            #endregion

            #region 交换变量值
            int a = 99;
            int b = 87;
            int temp;
            temp = a;
            a = b;
            b = temp;
            Console.WriteLine($"交换后A的值为:{a}B的值为:{b}");
            #endregion

            #region 时间转换
            int second = 987652;
            int hour, minute, day;
            day = second / 86400; // 1天 = 86400秒
            hour = (second - (day * 86400)) / 3600; // 1小时 = 3600秒
            minute = (second - (day * 86400 + hour * 3600)) / 60; // 1分钟 = 60秒
            second = second - (day * 86400 + hour * 3600 + minute * 60);
            Console.WriteLine($"转换后的时间为{day}天{hour}小时{minute}分钟{second}秒");
            #endregion
        }

    }
}