# C sharp_study_ZZ

**Repository Path**: YeTIngXY/c-sharp_study_-zz

## Basic Information

- **Project Name**: C sharp_study_ZZ
- **Description**: 周正的C#代码学习的仓库
- **Primary Language**: C#
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-09-07
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# 1.输入日期计算到现在的天数
> 代码展示

```
            Console.WriteLine("请输入年/月/日:");
            string str = Console.ReadLine();
            //拆分字符串
            char[] separtor = { '/' };//数组定义形式
            str.Split(separtor);//Split方法的用法
            String[] strArr = str.Split(separtor);
            int month = int.Parse(strArr[1]);//转化
            int sum = 0;
            int year = int.Parse(strArr[0]);
            int day = int.Parse(strArr[2]);
            switch (month)
            {

                case 1:
                    sum = 0+day;
                    break;
                case 2:
                    sum = 31+day;
                    //判断闰年;
                    if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))
                    {
                        sum += 1;
                        Console.WriteLine("是闰年");
                    }
                    else
                    {
                        Console.WriteLine("不是闰年");
                    }
                    break;
                case 3:
                    sum = 59 + day;
                    break;
                case 4:
                    sum = 90 + day;
                    break;
                case 5:
                    sum = 120 + day;
                    break;
                case 6:
                    sum = 151 + day;
                    break;
                case 7:
                    sum = 181 + day;
                    break;
                case 8:
                    sum = 212 + day;
                    break;
                case 9:
                    sum = 243 + day;
                    break;
                case 10:
                    sum = 273 + day;
                    break;
                case 11:
                    sum = 304 + day;
                    break;
                case 12:
                    sum = 334 + day;
                    break;
            }

            //计算
            Console.WriteLine("这是一年中的第{0}天", sum);
```
> 运行截图
> ![Day](Pictures/day.png)
# 2.穷举九宫格
> 运行代码

```
        static  void Main(string[] args)

        {

            Show();

            GetAnswer(0);

            Console.ReadLine();

        }
        static int[,] pu = new int[9, 9]
        {
        {0,0,0,7,2,8,0,0,0},
        {0,9,0,0,5,1,6,0,0},
        {0,0,0,0,6,0,0,8,2},
        {3,0,0,8,0,2,7,0,4},
        {1,7,4,0,3,0,0,2,0},
        {2,8,0,5,0,0,0,3,0},
        {0,1,0,3,0,0,2,0,0},
        {0,0,7,0,4,6,0,0,5},
        {0,0,6,1,0,0,0,4,9} 
        };

        static bool IsValid(int i, int j)
        {
            //验证函数
            int n = pu[i, j];
            int[] query = new int[9] { 0, 0, 0, 3, 3, 3, 6, 6, 6 };
            int t, u;
            //每一行每一列是否重复
            for (t = 0; t < 9; t++)
            {
                if ((t != i && pu[t, j] == n) || (t != j && pu[i, t] == n))
                    return false;
            }
            //每个九宫格是否重复
            for (t = query[i]; t < query[i] + 3; t++)
            {
                for (u = query[j]; u < query[j] + 3; u++)
                {
                    if ((t != i || u != j) && pu[t, u] == n)
                        return false;
                }
            }
            return true;
        }

        static void Show()
        {
            //显示函数
            for (var i = 0; i < 9; i++)
            {
                for (var j = 0; j < 9; j++)
                {
                    Console.Write(pu[i, j] + " ");
                }
                Console.WriteLine();
            }
            Console.WriteLine("----------------------------------------------");
        }

        static void GetAnswer(int n)
        {
            //求解函数
            if (n == 81)
            {//是否已经是最后一个格子
                Show();
                return;
            }
            int i = n / 9, j = n % 9;
            if (pu[i, j] != 0)
            {//如果当前格子不需要填数字，就跳到下一个格子
                GetAnswer(n + 1);
                return;
            }
            for (int k = 0; k < 9; k++)
            {
                pu[i, j]++;//对于九宫格数独解法，将定位到的格子数字加一，检测，一行或一列或一3*3格检测无解就回到开始
                if (IsValid(i, j))
                    GetAnswer(n + 1);//验证通过，就继续下一个
            }
            pu[i, j] = 0;  //如果上面的单元无解，还原，就回溯
            return;
        }
```
> 运行截图
> ![九宫格](Pictures/九宫格.png)