关于一年中的第几天，练手

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Linq;
  4 using System.Text;
  5 using System.Threading.Tasks;
  6 
  7 namespace 一年中第几天
  8 {
  9     class Program
 10     {
 11         static void Main(string[] args)
 12         {
 13             int year, month, date, num;
 14             Console.WriteLine("请输入年份：（1-9999）");
 15             year = Convert.ToInt32(Console.ReadLine());
 16             if (year >= 1 && year <= 9999)
 17             {
 18                 Console.WriteLine("请输入月份：");
 19                 month = Convert.ToInt32(Console.ReadLine());
 20                 if (month >= 1 && month <= 12)
 21                 {
 22                     Console.WriteLine("请输入日期：");
 23                     date = Convert.ToInt32(Console.ReadLine());
 24                     if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12 && date >= 1 && date <= 31)
 25                     {
 26                         Console.WriteLine("您输入的日期格式正确");
 27                         if (month == 1)
 28                         {
 29                             num = date;
 30                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 31                         }
 32                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 3)
 33                         {
 34                             num = 31 + 29 + date;
 35                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 36 
 37                         }
 38                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 3)
 39                         {
 40                             num = 31 + 28 + date;
 41                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 42                         }
 43                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 5)
 44                         {
 45                             num = 31 + 29 + 31 + 30 + date;
 46                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 47                         }
 48                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 5)
 49                         {
 50                             num = 31 + 28 + 31 + 30 + date;
 51                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 52                         }
 53                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 7)
 54                         {
 55                             num = 31 + 29 + 31 + 30 + 31 + 30 + date;
 56                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 57                         }
 58                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 7)
 59                         {
 60                             num = 31 + 28 + 31 + 30 + 31 + 30 + date;
 61                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 62                         }
 63 
 64                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 8)
 65                         {
 66                             num = 31 + 29 + 31 + 30 + 31 + 30 + 31 + date;
 67                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 68                         }
 69                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 8)
 70                         {
 71                             num = 31 + 28 + 31 + 30 + 31 + 30 + 31 + date;
 72                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 73                         }
 74 
 75                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 10)
 76                         {
 77                             num = 31 + 29 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + date;
 78                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 79                         }
 80                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 10)
 81                         {
 82                             num = 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + date;
 83                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 84                         }
 85                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 12)
 86                         {
 87                             num = 31 + 29 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + date;
 88                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 89                         }
 90                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 12)
 91                         {
 92                             num = 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + date;
 93                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
 94                         }
 95                     }
 96 
 97                     else if ((month == 4 || month == 6 || month == 9 || month == 11) && date >= 1 && date <= 30)
 98                     {
 99                         Console.WriteLine("您输入的日期格式正确");
100                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 4)
101                         {
102                             num = 31 + 29 + 31 + date;
103                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
104                         }
105                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 4)
106                         {
107                             num = 31 + 28 + 31 + date;
108                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
109                         }
110                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 6)
111                         {
112                             num = 31 + 29 + 31 + 30 + 31 + date;
113                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
114                         }
115                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 6)
116                         {
117                             num = 31 + 28 + 31 + 30 + 31 + date;
118                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
119                         }
120                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 9)
121                         {
122                             num = 31 + 29 + 31 + 30 + 31 + 30 + 31 + 31 + date;
123                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
124                         }
125                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 9)
126                         {
127                             num = 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + date;
128                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
129                         }
130                         if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 11)
131                         {
132                             num = 31 + 29 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + date;
133                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
134                         }
135 
136 
137 
138                         else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 11)
139                         {
140                             num = 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + date;
141                             Console.WriteLine("您输入的日期是当年的第" + num + "天");
142                         }
143                     }
144                     else if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 2 && date >= 1 && date <= 29)
145                     {
146                         Console.WriteLine("您输入的日期格式正确");
147                         num = 31 + 29;
148                         Console.WriteLine("您输入的日期是当年的第" + num + "天");
149                     }
150                     else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 2 && date >= 1 && date <= 28)
151                     {
152                         Console.WriteLine("您输入的日期格式正确");
153                         num = 31 + 28;
154                         Console.WriteLine("您输入的日期是当年的第" + num + "天");
155                     }
156 
157 
158                     else
159                     {
160                         Console.WriteLine("您输入的日期格式不对");
161                     }
162                 }
163                 else
164                 {
165                     Console.WriteLine("您输入的月份格式错误");
166                 }
167             }
168             else
169             {
170                 Console.WriteLine("您输入的年份格式错了");
171             }
172             Console.ReadLine();
173 
174         }
175     }
176 }