C# 如何遍历数组并创建一个列表来计算一个数字的重复次数

论坛之友

首先，我为我的英语道歉

如何遍历一个数组并创建一个列表来计算一个数字的重复次数，并按item2从高到低排序

我有以下数组：

int[] arrayNumeros= new int[10] {1,2,3,4,5,6,1,1,2,3}

我有以下清单：

List<Tuple<int, int>> contadorNumerosTotal = new List<Tuple<int, int>>();

---

非常感谢您抽出时间

以下内容将产生预期的结果：

int[] numbers = new int[] {1,2,3,4,5,6,1,1,2,3};

Dictionary<int, int> numberCount = new Dictionary<int, int>();

int len = numbers.Length;
for(int i = 0; i < len; i++)
{
    if (numberCount.ContainsKey(numbers[i]))
    {
        numberCount[numbers[i]]++;
    }
    else
    {
        numberCount[numbers[i]] = 1;
    }
}

// Sort by value if necessary. Otherwise loop through numberCount.
var sortednumberCount = numberCount.OrderByDescending(pair => pair.Value);
foreach (var number in sortednumberCount)
{
    Console.WriteLine("{0} -> {1}", number.Key, number.Value);
}

---

您可以使用以下内容：

List<Tuple<int, int>> contadorNumerosTotal =
    arrayNumeros.GroupBy (i => i).Select (ints => new Tuple<int, int> (ints.Key, ints.Count ())).ToList ();
contadorNumerosTotal.Sort ((tuple, tuple1) => tuple1.Item2.CompareTo (tuple.Item2));

int [] arrayNumeros = new int[10] {1, 2, 3, 4, 5, 6, 1, 1, 2, 3};
List<Tuple<int, int>> contadorNumerosTotal =
    arrayNumeros.GroupBy (i => i).Select (ints => new Tuple<int, int> (ints.Key, ints.Count ())).ToList ();
contadorNumerosTotal.Sort ((tuple, tuple1) => tuple1.Item2.CompareTo (tuple.Item2));
foreach (var count in contadorNumerosTotal)
    Console.WriteLine ($"{count.Item1} -> {count.Item2}");
Console.ReadLine ();

其结果如下：

1 -> 3
2 -> 2
3 -> 2
4 -> 1
5 -> 1
6 -> 1

阅读有关groupBy的更多信息

---

使用Linq GROUPBY可能的重复可以查看使用线性搜索算法，如果您的目标只是找到重复的元素很多感谢Tristan Gibson。这正是我所需要的。一种问候语。然而，这种问候语的类型与他想要的不同。顺便说一句，解释也没什么坏处。

List<Tuple<int, int>> contadorNumerosTotal =
    arrayNumeros.GroupBy (i => i).Select (ints => new Tuple<int, int> (ints.Key, ints.Count ())).ToList ();
contadorNumerosTotal.Sort ((tuple, tuple1) => tuple1.Item2.CompareTo (tuple.Item2));

int [] arrayNumeros = new int[10] {1, 2, 3, 4, 5, 6, 1, 1, 2, 3};
List<Tuple<int, int>> contadorNumerosTotal =
    arrayNumeros.GroupBy (i => i).Select (ints => new Tuple<int, int> (ints.Key, ints.Count ())).ToList ();
contadorNumerosTotal.Sort ((tuple, tuple1) => tuple1.Item2.CompareTo (tuple.Item2));
foreach (var count in contadorNumerosTotal)
    Console.WriteLine ($"{count.Item1} -> {count.Item2}");
Console.ReadLine ();

1 -> 3
2 -> 2
3 -> 2
4 -> 1
5 -> 1
6 -> 1

int[] arrayNumeros= new int[10] {1,2,3,4,5,6,1,1,2,3};

var result = arrayNumeros
    .GroupBy( e => e )
    .ToDictionary( e => e.Key, e => e.Count() )
    .OrderByDescending( e => e.Value )
    .ThenBy( e => e.Key )
    .Select( e => Tuple.Create( e.Key, e.Value ) )
    .ToList();