根据某些条件在c＃中对列表进行排序

Question

我想以最有效的方式对“条目”列上给定列表中的条目进行排序。下面是我的i条目外观的示例。

#No Detail                                 Entry          Number          Rate
1   Carpool at 5$                          C              1               5
    Carpool at 5$                          H              2               5

2   Played Cricket at 2$                   X              1               2
    Played Cricket at 2$                   O              2               2

3   Done something at 4$                  ""              0               4

4   Done something else at 9$              M              1               9

5   Watched movie at 6$                    B              1               6
    Watched movie at 6$                    Z              2               6

有关数据的一些解释：

1. 列表中没有可用的列。我只是在这里提到，以提供有关条目的详细信息。
2. 1,2,5是特殊的俱乐部条目，应在编号列设置为1的条目上进行排序。 他们的速率和描述将是相同的，并且 数字将是1和2。
3. 有可能有些条目包含 条目值为空，此类条目的编号将设置为0。例如3
4. 有可能有些条目包含 单个Entry值，将没有成对和Number列 这样的条目将被设置为1，并且在 具有相同描述和比率的列表，“数字”列设置为2。例如＃4。
5. 虽然在“条目”列上对俱乐部条目进行排序，但仅考虑“条目” 将Number设置为1，其他条目也应一起标记。

我想按照上述规则通过升序或降序对Entry列进行排序。

我的解决方案：

using System.Collections.Generic;
using System.Linq;

namespace ConsoleApplication1
{
    internal class Data
    {
        public string Detail { get; set; }
        public string Entry { get; set; }
        public int Number { get; set; }
        public int Rate { get; set; }
    }

    internal class Program
    {
        private static void Main(string[] args)
        {
            List<Data> entries = new List<Data>();

            // Clubbed entry...While sorting only consider entry with Number set to 1. They will have same rate and Detail.
            entries.Add(new Data() { Detail = "Carpool at 5$", Entry = "C", Number = 1, Rate = 5 });
            entries.Add(new Data() { Detail = "Carpool at 5$", Entry = "H", Number = 2, Rate = 5 });

            // Clubbed entry
            entries.Add(new Data() { Detail = "Played Cricket at 2$", Entry = "X", Number = 1, Rate = 2 });
            entries.Add(new Data() { Detail = "Played Cricket at 2$", Entry = "O", Number = 2, Rate = 2 });

            // entry which have empty Entry value such entries will have Number set to 0
            entries.Add(new Data() { Detail = "Done something at 4$", Entry = "", Number = 0, Rate = 4 });

            // entry which will not have an pair and Number column for such entries would be set to 1 and 
            // there wouldn't be any entry in list which have same detail and rate with Number coloumn set to 2
            entries.Add(new Data() { Detail = "Done something else at 9$", Entry = "M", Number = 1, Rate = 9 });

            // Clubbed entry
            entries.Add(new Data() { Detail = "Watched movie at 6$", Entry = "B", Number = 1, Rate = 6 });
            entries.Add(new Data() { Detail = "Watched movie at 6$", Entry = "Z", Number = 2, Rate = 6 });

            // Sorting on Entry Coloumn
            var sortedList = entries.GroupBy(x => x.Detail).OrderBy(x => x.FirstOrDefault(y => y.Number <= 1).Entry).SelectMany(x => x).ToList();

        }
    }
}

输出：

Detail                                 Entry          Number          Rate  
Done something at 4$                  ""              0               4

Watched movie at 6$                    B              1               6
Watched movie at 6$                    Z              2               6

Carpool at 5$                          C              1               5
Carpool at 5$                          H              2               5

Done something else at 9$              M              1               9

Played Cricket at 2$                   X              1               2
Played Cricket at 2$                   O              2               2

问题：

• 我的解决方案不考虑费率，仅基于明细的组可以 可以修改吗？
  • 可以使用IComparer来完成它，就像我其余代码中使用IComparer进行排序一样吗？​​

Answer 1

您可以通过创建匿名对象来按“费率”和“详细信息”分组。如果您使用的是size_t i = 0; s = malloc(1); /* TODO: check for s != NULL */ while ((c = getchar()) != '\n') { s[i] = c; i++; s = realloc(s, i + 1); /* TODO: check for s != NULL */ } s[i] = '\0'; ，则应该处理FirstOrDefault返回null的可能性。如果您不应该拥有不包含0或1的?.的组，则应该只使用Number。您应该根据First对组中的成员进行排序：

Number