c# - 如何在数组中找到重复项并显示它们出现的次数？

Question

我正在编写一个代码，打印出数组中重复的整数以及它们出现的次数。我不允许使用 LINQ，只是一个简单的代码。我想我很接近但对如何获得正确的输出感到困惑:

class Program
{
    static void Main(string[] args)
    {              
        int[] array = { 10, 5, 10, 2, 2, 3, 4, 5, 5, 6, 7, 8, 9, 11, 12, 12 };
        int count = 1;
        for (int i = 0; i < array.Length; i++)
        {
            for (int j = i; j < array.Length - 1 ; j++)
            {

               if(array[j] == array[j+1])
                  count = count + 1;
            }
            Console.WriteLine("\t\n " + array[i] + "occurse" + count);
            Console.ReadKey();
        }
    }
}

Answer 1

由于您不能使用 LINQ，因此您可以使用集合和循环来代替:

static void Main(string[] args)
{              
    int[] array = { 10, 5, 10, 2, 2, 3, 4, 5, 5, 6, 7, 8, 9, 11, 12, 12 };
    var dict = new Dictionary<int, int>();
    
    foreach(var value in array)
    {
        // When the key is not found, "count" will be initialized to 0
        dict.TryGetValue(value, out int count);
        dict[value] = count + 1;
    }
    
    foreach(var pair in dict)
        Console.WriteLine("Value {0} occurred {1} times.", pair.Key, pair.Value);
    Console.ReadKey();
}