我一直在使用从函数调用中返回的c#字符串[]数组。我可以强制转换为Generic集合,但我想知道是否有更好的方法,可能是使用临时数组。

从c#数组中删除重复项的最佳方法是什么?


当前回答

int size = a.Length;
        for (int i = 0; i < size; i++)
        {
            for (int j = i + 1; j < size; j++)
            {
                if (a[i] == a[j])
                {
                    for (int k = j; k < size; k++)
                    {
                        if (k != size - 1)
                        {
                            int temp = a[k];
                            a[k] = a[k + 1];
                            a[k + 1] = temp;

                        }
                    }
                    j--;
                    size--;
                }
            }
        }

其他回答

下面经过测试和工作的代码将从数组中删除重复项。你必须包括系统。集合名称空间。

string[] sArray = {"a", "b", "b", "c", "c", "d", "e", "f", "f"};
var sList = new ArrayList();

for (int i = 0; i < sArray.Length; i++) {
    if (sList.Contains(sArray[i]) == false) {
        sList.Add(sArray[i]);
    }
}

var sNew = sList.ToArray();

for (int i = 0; i < sNew.Length; i++) {
    Console.Write(sNew[i]);
}

如果你愿意,你可以把它打包成一个函数。

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


namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
             List<int> listofint1 = new List<int> { 4, 8, 4, 1, 1, 4, 8 };
           List<int> updatedlist= removeduplicate(listofint1);
            foreach(int num in updatedlist)
               Console.WriteLine(num);
        }


        public static List<int> removeduplicate(List<int> listofint)
         {
             List<int> listofintwithoutduplicate= new List<int>();


              foreach(var num in listofint)
                 {
                  if(!listofintwithoutduplicate.Any(p=>p==num))
                        {
                          listofintwithoutduplicate.Add(num);
                        }
                  }
             return listofintwithoutduplicate;
         }
    }



}
public static int RemoveDuplicates(ref int[] array)
{
    int size = array.Length;

    // if 0 or 1, return 0 or 1:
    if (size  < 2) {
        return size;
    }

    int current = 0;
    for (int candidate = 1; candidate < size; ++candidate) {
        if (array[current] != array[candidate]) {
            array[++current] = array[candidate];
        }
    }

    // index to count conversion:
    return ++current;
}
protected void Page_Load(object sender, EventArgs e)
{
    string a = "a;b;c;d;e;v";
    string[] b = a.Split(';');
    string[] c = b.Distinct().ToArray();

    if (b.Length != c.Length)
    {
        for (int i = 0; i < b.Length; i++)
        {
            try
            {
                if (b[i].ToString() != c[i].ToString())
                {
                    Response.Write("Found duplicate " + b[i].ToString());
                    return;
                }
            }
            catch (Exception ex)
            {
                Response.Write("Found duplicate " + b[i].ToString());
                return;
            }
        }              
    }
    else
    {
        Response.Write("No duplicate ");
    }
}

可能是不存储重复元素的hashset,它会默默地忽略添加请求 重复。

static void Main()
{
    string textWithDuplicates = "aaabbcccggg";     

    Console.WriteLine(textWithDuplicates.Count());  
    var letters = new HashSet<char>(textWithDuplicates);
    Console.WriteLine(letters.Count());

    foreach (char c in letters) Console.Write(c);
    Console.WriteLine("");

    int[] array = new int[] { 12, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2 };

    Console.WriteLine(array.Count());
    var distinctArray = new HashSet<int>(array);
    Console.WriteLine(distinctArray.Count());

    foreach (int i in distinctArray) Console.Write(i + ",");
}