C# (String.StartsWith && !String.EndsWith && !String.Contains) 使用列表

Question

我是 C# 的新手，遇到了一些问题。

我有 2 个列表、2 个字符串和一个 getCombinations(string) 方法 将字符串的所有组合作为列表返回；

我如何验证 subjectStrings 元素是否不存在 StartWith && !EndsWith && !Contains(或 !StartWith && !EndsWith && Contains 等) 对于 startswithString、endswithString 和 containsString 的每个组合？

这是我在 StartWith && !EndsWith 中的代码 (如果你想看到它运行:http://ideone.com/y8JZkK)

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

    public class Test
    {
            public static void Main()
            {
                    List<string> validatedStrings = new List<string>();
                    List<string> subjectStrings = new List<string>()
                    {
                            "con", "cot", "eon", "net", "not", "one", "ten", "toe", "ton",
                                    "cent", "cone", "conn", "cote", "neon", "none", "note", "once", "tone",
                                    "cento", "conte", "nonce", "nonet", "oncet", "tenon", "tonne",
                                    "nocent","concent", "connect"
                    }; //got a more longer wordlist

                    string startswithString = "co";
                    string endswithString = "et";

                    foreach(var z in subjectStrings)
                    {
                        bool valid = false;
                        foreach(var a in getCombinations(startswithString))
                        {
                            foreach(var b in getCombinations(endswithString))
                            {
                                if(z.StartsWith(a) && !z.EndsWith(b))
                                {
                                        valid = true;
                                        break;
                                }
                            }
                            if(valid)
                            {
                                break;
                            }
                        }
                        if(valid)
                        {
                            validatedStrings.Add(z);
                        }
                    }

                    foreach(var a in validatedStrings)
                    {
                            Console.WriteLine(a);
                    }
                    Console.WriteLine("\nDone");
            }


            static List<string> getCombinations(string s)
            {
                    //Code that calculates combinations
                    return Permutations.Permutate(s);
            }
    }

    public class Permutations
    {
            private static List<List<string>> allCombinations;

            private static void CalculateCombinations(string word, List<string> temp)
            {
                    if (temp.Count == word.Length)
                    {
                            List<string> clone = temp.ToList();
                            if (clone.Distinct().Count() == clone.Count)
                            {
                                    allCombinations.Add(clone);
                            }
                            return;
                    }

                    for (int i = 0; i < word.Length; i++)
                    {
                            temp.Add(word[i].ToString());
                            CalculateCombinations(word, temp);
                            temp.RemoveAt(temp.Count - 1);
                    }
            }

            public static List<string> Permutate(string str)
            {
                    allCombinations = new List<List<string>>();
                    CalculateCombinations(str, new List<string>());
                    List<string> combinations = new List<string>();
                    foreach(var a in allCombinations)
                    {
                            string c = "";
                            foreach(var b in a)
                            {
                                    c+=b;
                            }
                            combinations.Add(c);
                    }
                    return combinations;
            }
    }

输出:

    con 
    cot
    cone
    conn
    cote <<<
    conte <<<
    concent
    connect

    Done

如果(z.StartsWith(a) && !z.EndsWith(b)) var b 可以是“et”和“te”，但 cote 和 conte 以“te”结尾， 为什么它仍然添加到我的验证字符串中？

提前致谢。

Answer 1

z.StartsWith(a) && !z.EndsWith(b)

检查下面的组合

z ="cote"
a ="co"
b ="te"

所以 z 以“co”开头且 z 不以“te”结尾，您的条件通过并且 cote 将添加到列表中

我会尝试如下

var sw =getCombinations(startswithString);
var ew = getCombinations(endswithString);


var result = subjectStrings.Where(z=> 
    sw.Any(x=>z.StartsWith(x) && 
        !ew.Any(y=>z.EndsWith(y))))
        .ToList();

DEMO

输出:

con
cot
cone
conn
concent
connect