C# 如何在C中为int列表构建直方图#

可能重复：

---

我有一个int列表，

list demoList

，它类似于

{1,2,1,1,1,3,2,1}

，我想写一个LINQ语句，从该列表中获得出现次数最多的数字，在我的例子中是

1

使用

groupby

子句

var groups = 
    from i in demoList
    group i by i into g
    select new { Value = g.Key, Count = g.Count() }

从这里你可以说

var max = groups.Max(g => g.Count);
groups.Where(g => g.Count == max).Select (g => g.Value); // { 1 }

编辑：如果您还想知道哪个数字出现的频率：

var appearances = demoList.GroupBy(i => i)
    .OrderByDescending(grp => grp.Count())
    .Select(grp => new { Num = grp.Key, Count = grp.Count() });
if (appearances.Any())
{
    int highestAppearanceNum = appearances.First().Num;     // 1
    int highestAppearanceCount = appearances.First().Count; // 5
}

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我提前道歉：

        List<int> demoList = new List<int>() { 1, 2, 1, 1, 1, 3, 2, 1 };

        Dictionary<int,int> keyOrdered = demoList.GroupBy(i => i)
            .Select(i => new { i.Key, Count = i.Count() })
            .OrderBy(i=>i.Key)
            .ToDictionary(i=>i.Key, i=>i.Count);

        var max = keyOrdered.OrderByDescending(i=>i.Value).FirstOrDefault();

        List<string> histogram = new List<string>();

        for (int i = max.Value; i >-1 ; i--)
        {
            histogram.Add(string.Concat(keyOrdered.Select(t => t.Value>i?"| ":"  ")));
        }

        histogram.Add(string.Concat(keyOrdered.Keys.OrderBy(i => i).Select(i => i.ToString() + " ")));

        histogram.ForEach(i => Console.WriteLine(i));

        Console.WriteLine(Environment.NewLine);
        Console.WriteLine("Max: {0}, Count:{1}", max.Key, max.Value);

List demoList=newlist（）{1,2,1,1,1,3,2,1}；
Dictionary keyOrdered=demoList.GroupBy（i=>i）
.Select（i=>new{i.Key，Count=i.Count（）}）
.OrderBy（i=>i.Key）
.ToDictionary（i=>i.Key，i=>i.Count）；
var max=keyorded.OrderByDescending（i=>i.Value）.FirstOrDefault（）；
列表直方图=新列表（）；
对于（int i=最大值；i>-1；i--）
{
添加（string.Concat（keyOrdered.Select（t=>t.Value>i？”）；
}
Add（string.Concat（keyOrdered.Keys.OrderBy（i=>i）.Select（i=>i.ToString（）+））；
histogram.ForEach（i=>Console.WriteLine（i））；
Console.WriteLine（Environment.NewLine）；
WriteLine（“Max:{0}，Count:{1}”，Max.Key，Max.Value）；

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当我读到这个标题时，我想到了这一点，这让我笑了。。（prolly也充满了bug！）

这是dup，但这个问题非常清楚，格式也更好；）

 int highestAppearanceNum = demoList.GroupBy(i => i)
            .OrderByDescending(grp => grp.Count())
            .Select(grp => grp.First())
            .First();

var appearances = demoList.GroupBy(i => i)
    .OrderByDescending(grp => grp.Count())
    .Select(grp => new { Num = grp.Key, Count = grp.Count() });
if (appearances.Any())
{
    int highestAppearanceNum = appearances.First().Num;     // 1
    int highestAppearanceCount = appearances.First().Count; // 5
}

        List<int> demoList = new List<int>() { 1, 2, 1, 1, 1, 3, 2, 1 };

        Dictionary<int,int> keyOrdered = demoList.GroupBy(i => i)
            .Select(i => new { i.Key, Count = i.Count() })
            .OrderBy(i=>i.Key)
            .ToDictionary(i=>i.Key, i=>i.Count);

        var max = keyOrdered.OrderByDescending(i=>i.Value).FirstOrDefault();

        List<string> histogram = new List<string>();

        for (int i = max.Value; i >-1 ; i--)
        {
            histogram.Add(string.Concat(keyOrdered.Select(t => t.Value>i?"| ":"  ")));
        }

        histogram.Add(string.Concat(keyOrdered.Keys.OrderBy(i => i).Select(i => i.ToString() + " ")));

        histogram.ForEach(i => Console.WriteLine(i));

        Console.WriteLine(Environment.NewLine);
        Console.WriteLine("Max: {0}, Count:{1}", max.Key, max.Value);