Question

我一直在努力找出将字符串中的单词组合起来以组合该字符串的最佳方法。我正在尝试为一个课程项目做这件事。如果字符串是“快速狐狸”，我需要找到一种输出“Thequick fox”，“quickfox”和“thequickfox”的方法。我尝试过使用string.split并将它们粘合在一起，但运气不好。问题是字符串输入可以是任何大小。

Answer 1

我决定试试这个很有趣。这里的想法是将更大的问题分解为更小的子问题。所以我首先开始使用0和1空格的字符串。我看到0空格，唯一可能的组合是字符串项。有一个空格，我可以有空间。

然后我只需要递归划分问题，直到得到其中一个基本案例。因此，对于分割数组中的Skip元素，以2为增量。这样我最终可以保证得到一个基本情况。一旦我这样做，我再次运行程序并找出如何将其所有结果添加到我当前的组合中。

以下是代码：

class Program
{

    static void Main(string[] args)
    {
        string test1 = "fox";
        string test2 = "The quick";
        string test3 = "The quick fox";
        string test4 = "The quick fox says";
        string test5 = "The quick fox says hello";

        var splittest1 = test1.Split(' ');
        var splittest2 = test2.Split(' ');
        var splittest3 = test3.Split(' ');
        var splittest4 = test4.Split(' ');
        var splittest5 = test5.Split(' ');

        var ans1 = getcombinations(splittest1);
        var ans2 = getcombinations(splittest2);
        var ans3 = getcombinations(splittest3);
        var ans4 = getcombinations(splittest4);
        var ans5 = getcombinations(splittest5);
    }




    static List<string> getcombinations(string[] splittest)
    {
        var combos = new List<string>();
        var numspaces = splittest.Count() - 1;
        if (numspaces == 1)
        {
            var addcombos = AddTwoStrings(splittest[0], splittest[1]);
            var withSpacesCurrent = addcombos.Item1;
            var noSpacesCurrent = addcombos.Item2;
            combos.Add(withSpacesCurrent);
            combos.Add(noSpacesCurrent);
        }
        else if (numspaces == 0)
        {
            combos.Add(splittest[0]);
        }
        else
        {
            var addcombos = AddTwoStrings(splittest[0], splittest[1]);
            var withSpacesCurrent = addcombos.Item1;
            var noSpacesCurrent = addcombos.Item2;
            var futureCombos = getcombinations(splittest.Skip(2).ToArray());
            foreach (var futureCombo in futureCombos)
            {
                var addFutureCombos = AddTwoStrings(withSpacesCurrent, futureCombo);
                var addFutureCombosNoSpaces = AddTwoStrings(noSpacesCurrent, futureCombo);

                var combo1 = addFutureCombos.Item1;
                var combo2 = addFutureCombos.Item2;
                var combo3 = addFutureCombosNoSpaces.Item1;
                var combo4 = addFutureCombosNoSpaces.Item2;

                combos.Add(combo1);
                combos.Add(combo2);
                combos.Add(combo3);
                combos.Add(combo4);
            }
        }



        return combos;
    }

    static Tuple<string, string> AddTwoStrings(string a, string b)
    {
        return Tuple.Create(a + " " + b, a + b);
    }

}
}

Answer 2

这就是我如何使用它，不确定它是否是最好的算法。

public class Program
{
    public static void Main(string[] args)
    {
        Console.WriteLine("Enter a string");

        string input = Console.ReadLine();

        //split the input string into an array
        string[] arrInput = input.Split(' ');

        Console.WriteLine("The combinations are...");

        //output the original string
        Console.WriteLine(input);

        //this loop decide letter combination
        for (int i = 2; i <= arrInput.Length; i++)
        {
            //this loop decide how many outputs we would get for a letter combination
            //for ex. we would get 2 outputs in a 3 word string if we combine 2 words
            for (int j = i-1; j < arrInput.Length; j++)
            {
                int end = j; // end index
                int start = (end - i) + 1; //start index

                string output = Combine(arrInput, start, end);

                Console.WriteLine(output);
            }
        }

        Console.ReadKey();
    }

    //combine array into a string with space except from start to end
    public static string Combine(string[] arrInput, int start, int end) {
        StringBuilder builder = new StringBuilder();
        bool combine = false;

        for (int i = 0; i < arrInput.Length; i++) {
            //first word in the array... don't worry
            if (i == 0) {
                builder.Append(arrInput[i]);
                continue;
            }
            //don't append " " if combine is true
            combine = (i > start && i <= end) ? true : false;

            if (!combine)
            {
                builder.Append(" ");
            }
            builder.Append(arrInput[i]);
        }

        return builder.ToString();
    }
}

如何删除空格以组合字符串

2 个答案: