Question

我是C＃的新手，我遇到了问题。

我有2个List，2个字符串和一个getCombinations（字符串）方法返回字符串的所有组合作为List;

如何验证subjectStrings元素是否没有 StartWith＆amp;＆amp; ！EndsWith＆amp;＆amp; ！包含（或！StartWith＆amp;＆amp;！EndsWith＆amp;＆amp;包含等）对于startswithString，endswithString和containsString？

的每个组合

这是我的代码在StartWith＆amp;＆amp; ！以。。结束（如果你想看到它正在运行：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

if（z.StartsWith（a）＆amp;＆amp;！z.EndsWith（b）） var b可以是＆＃34; et＆＃34;和＆＃34; te＆＃34;，但cote和conte结束＆＃34; te＆＃34;，为什么它仍然在我的验证字符串中添加？

提前致谢。

Answer 1

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

检查以下组合

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

所以z以“co”开头，z不以“te”结尾，条件通过，cote将添加到列表

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

Answer 2

                            foreach(var b in getCombinations(endswithString))
                        {
                            if(z.StartsWith(a) && !z.EndsWith(b))
                            {
                                    valid = true;
                                    break;
                            }
                        }

这里只要匹配！z.EndsWith（b）就设置有效为true，并且您没有遍历可用的整个排列列表。因为“cote”不以“et”结尾，所以它是匹配，有效设置为true，代码中断。这就是为什么“cote”被添加到有效字符串列表中的原因。 “conte”也是如此。

您想要做的是：

    List<string> startsWithCombination = getCombinations("co");
    List<string> endsWithCombination = getCombinations("et");

    foreach (var z in subjectStrings)
    {
        bool isStartMatchFound = startsWithCombination.Any(b => z.StartsWith(b));

        if (isStartMatchFound)
        {
            bool isEndMatchFound = endsWithCombination.Any(b => z.EndsWith(b));

            if (!isEndMatchFound)
            {
                validatedStrings.Add(z);
            }
        }
    }

使用List的C＃（String.StartsWith＆amp;＆amp;！String.EndsWith＆amp;＆amp;！String.Contains）

2 个答案: