如何在按钮之间平均分割字符串字符？

Question

I have an array of string elements of various words. I need the characters of each word be split equally into the text component of 3 buttons. For example, the array could hold the elements "maybe", "his", "car" . In each game one of these words will be pulled from the array and its characters divided into the 3 buttons. For example, button 1 will have "ma" , button 2 will have "yb" and button 3 "e" (for the word maybe). I then hide the text element of one button for the user to drag and drop the correct missing letter(s) into the space. The purpose of the game is to help children learn to spell. Does anyone know how I could go about dividing the characters equally into the 3 buttons?

Answer 1

Here's a function that would split the word into the amount of segments you want. You can then iterate over that list to set each segment to a button.Text.

public List<string> SplitInSegments(string word, int segments)
{
    int wordLength = word.Length;

    // The remainder tells us how many segments will get an extra letter
    int remainder = wordLength % segments;

    // The base length of a segment
    // This is a floor division, because we're dividing ints.
    // So 5 / 3 = 1
    int segmentLength = wordLength / segments;

    var result = new List<string>();
    int startIndex = 0;
    for (int i = 0; i < segments; i++)
    {
        // This segment may get an extra letter, if its index is smaller then the remainder
        int currentSegmentLength = segmentLength + (i < remainder ? 1 : 0);

        string currentSegment = word.Substring(startIndex, currentSegmentLength);

        // Set the startindex for the next segment.
        startIndex += currentSegmentLength;

        result.Add(currentSegment);
    }

    return result;
}

usage:

// returns ["ma", "yb", "e"]
var segments = SplitInSegments("maybe", 3);

Edit

I like the fact that this is for teaching children. So here comes. Regarding your question on splitting the string based on specific letter sequences: After you've split the string using regex, you will have an array of strings. Then determine the amount of items in the splitted string and concatenate or split further based on the number of segments:

// sequences to split on first
static readonly string[] splitSequences = {
    "el",
    "ol",
    "bo"
};

static readonly string regexDelimiters = string.Join('|', splitSequences.Select(s => "(" + s + ")"));

// Method to split on sequences
public static List<string> SplitOnSequences(string word)
{
    return Regex.Split(word, regexDelimiters).Where(s => !string.IsNullOrEmpty(s)).ToList();
}

public static List<string> SplitInSegments(string word, int segments)
{
    int wordLength = word.Length;

    // The remainder tells us how many segments will get an extra letter
    int remainder = wordLength % segments;

    // The base length of a segment
    // This is a floor division, because we're dividing ints.
    // So 5 / 3 = 1
    int segmentLength = wordLength / segments;

    var result = new List<string>();
    int startIndex = 0;
    for (int i = 0; i < segments; i++)
    {
        // This segment may get an extra letter, if its index is smaller then the remainder
        int currentSegmentLength = segmentLength + (i < remainder ? 1 : 0);

        string currentSegment = word.Substring(startIndex, currentSegmentLength);

        // Set the startindex for the next segment.
        startIndex += currentSegmentLength;

        result.Add(currentSegment);
    }

    return result;
}

// Splitword will now always return 3 segments
public static List<string> SplitWord(string word)
{
    if (word == null)
    {
        throw new ArgumentNullException(nameof(word));
    }

    if (word.Length < 3)
    {
        throw new ArgumentException("Word must be at least 3 characters long", nameof(word));
    }

    var splitted = SplitOnSequences(word);

    var result = new List<string>();
    if (splitted.Count == 1)
    {
        // If the result is not splitted, just split it evenly.
        result = SplitInSegments(word, 3);
    }
    else if (splitted.Count == 2)
    {
        // If we've got 2 segments, split the shortest segment again.
        if (splitted[1].Length > splitted[0].Length
            && !splitSequences.Contains(splitted[1]))
        {
            result.Add(splitted[0]);
            result.AddRange(SplitInSegments(splitted[1], 2));
        }
        else
        {
            result.AddRange(SplitInSegments(splitted[0], 2));
            result.Add(splitted[1]);
        }
    }
    else // splitted.Count >= 3
    { 
        // 3 segments is good.
        result = splitted;

        // More than 3 segments, combine some together.
        while (result.Count > 3)
        {
            // Find the shortest combination of two segments
            int shortestComboCount = int.MaxValue;
            int shortestComboIndex = 0;
            for (int i = 0; i < result.Count - 1; i++)
            {
                int currentComboCount = result[i].Length + result[i + 1].Length;
                if (currentComboCount < shortestComboCount)
                {
                    shortestComboCount = currentComboCount;
                    shortestComboIndex = i;
                }
            }

            // Combine the shortest segments and replace in the result.
            string combo = result[shortestComboIndex] + result[shortestComboIndex + 1];
            result.RemoveAt(shortestComboIndex + 1);
            result[shortestComboIndex] = combo;
        }
    }

    return result;
}

Now when you call the code:

// always returns three segments.
var splitted = SplitWord(word);

Answer 2

Here is another approach.

First make sure that the word can be divided by the desired segments (add a dummy space if necessary) , then use a Linq statement to get your parts and when adding the result trim away the dummy characters.

public static string[] SplitInSegments(string word, int segments)
{
    while(word.Length %  segments != 0) { word+=" ";}
    var result = new List<string>();
    for(int x=0; x < word.Count(); x += word.Length / segments)
    result.Add((new string(word.Skip(x).Take(word.Length / segments).ToArray()).Trim()));
    return result.ToArray();
}

Answer 3

You can split your string into a list and generate buttons based on your list. The logic for splitting the word into a string list would be something similar to this:

string test = "maybe"; List list = new List();

    int i = 0, len = 2;
    while(i <= test.Length)
    {
        int lastIndex = test.Length - 1;
        list.Add(test.Substring(i, i + len > lastIndex? (i + len) - test.Length : len));
        i += len;       
    }

HTH