将字符串中的每个单词添加并计数到链表中

Question

我首先要说我还没有完全理解 OOP。

我需要一个例程来遍历字符串中的每个单词，检查它是否在我的链表中，如果不是，则将其添加为节点，或者增加现有节点的计数，如果它在列表。

这是我所拥有的：

private void CountWords(string cleanString)
        {
            WordNode nextNode, prevNode;
            WordNode addNode;
            foreach (string stringWord in cleanString.Split(' '))
            {
                if (head == null)
                {
                    // No items in list, add to the beginning
                    addNode = new WordNode(stringWord);
                    head = addNode;
                }
                else
                {
                    if (String.Compare(stringWord, head.Word) < 0)
                    {
                        // If stringWord belongs at the beginning of the list, put it there
                        addNode = new WordNode(stringWord);
                        addNode.NextWord = head;
                        head = addNode;
                    }
                    else if (String.Compare(stringWord, head.Word) == 0)
                    {
                        // If stringWord is equal to head.Word, increase count
                        addNode.Count += 1;
                    }
                    else
                    {
                        prevNode = head;
                        nextNode = head.NextWord;
                        // If it doesn't belong at the beginning, cycle through the list until you find where it does belong
                        while ((nextNode != null) && (String.Compare(nextNode.Word, addNode.Word) < 0))
                        {
                            prevNode = nextNode;
                            nextNode = nextNode.NextWord;
                        }
                        if (nextNode == null)
                        {
                            prevNode.NextWord = addNode;
                        }
                        else
                        {
                            prevNode.NextWord = addNode;
                            addNode.NextWord = nextNode;
                        }
                    }

                }
            }
        }

在此之前，我尝试 addNode = new WordNode(stringWord); 在每次迭代开始时通过“for each word in string”循环，但这会重新定义类和将计数重置为 1。目前，我无法增加计数，因为 addNode.Count += 1; 未定义。我希望我可以检查 stringWord 是否在链接列表中，如果是，则将 stringWord.count 加一，但这会引发错误。

现在看这个，我认为 addNode.Count += 1; 属于 while 循环下面几行...

这是我的 WordNode 类：

class WordNode
    {
        // constants

        // variables
        private string data;            // this is our only data, so also key
        private int count;
        private WordNode next;          // this is reference to next Node

        // constructors
        public WordNode(string newValue)
        {
            Word = newValue;
            count = 1;
            NextWord = null;
        }

        // methods
        public string Word
        {
            get
            {
                return data;
            }
            set
            {
                data = value;
            }
        }

        public int Count
        {
            get
            {
                return count;
            }
            set
            {
                count = value;
            }
        }

        public WordNode NextWord
        {
            get
            {
                return next;
            }
            set
            {
                next = value;
            }
        }
    }

Answer 1

这看起来像是 Dictionary 或 here 的工作

Dictionary<string,int> myDict = new Dictionary<string,int>();

foreach(string str in listOfWords)
{
   myDict.add(str,0);
}

foreach(string x in cleanText.split(' '))
{
if(myDict.ContainsKey(x))
   myDict[x]+=1;
}

在运行 foreach 之后，myDict 将包含“词袋”中每个词的计数。

编辑

if(myDict == null)
   myDict = new Dictionary<string,int>(); //assuming running tally at higher scope.


foreach(string x in cleanText.split(' '))
{
if(myDict.ContainsKey(x))
   myDict[x]+=1;
else
   myDict.add(x,1);
}

Answer 2

试试这个：

private void CountWords(string cleanString)
{
    foreach (string stringWord in cleanString.Split(' '))
    {
        if (head == null)
        {
            head = new WordNode(stringWord);
        }
        else
        {
            var last = (WordNode)null;
            var current = head;
            do
            {
                if (current.Word == stringWord)
                {
                    break;
                }
                last = current;
                current = current.NextWord;
            } while (current != null);
            if (current != null)
            {
                current.Count++;
            }
            else
            {
                last.NextWord = new WordNode(stringWord);
            }
        }
    }
}

另一种方法是使用 linq：

var query =
    cleanString
        .Split(' ')
        .ToLookup(x => x)
        .Select(x => new
        {
            Word = x.Key,
            Count = x.Count(),
        });

Answer 3

听起来你只是想练习制作一个链表，所以这可能没有帮助，但更简单的解决方案是像字典一样使用键/值对。

Dictionary<string, int> Words = new Dictionary<string, int>();
string wordsList = "a list of words for testing a list of words for testing";
foreach (string word in wordsList.Split(' '))
{
   if (Words[word] == null)
      Words[word] = 1;
   else
      Words[word] += 1;
}
System.Console.WriteLine("testing: {0}", Words["testing"]); //result- testing: 2

按字符串索引单词字典的结果会返回单词的个数。