在C＃中比较一个2D和一个一维数组？

Question

我只是想编写比较一维数组与二维数组的代码......我正在编写一个编译器，并且想要比较一个包含我的代码的一维数组和其中我已经创建了一个符号表的一维数组。 我写了代码，但它不工作。

for (int x = 0; x < symboltable1.Length; x++) 
{ 
    for (int y = 0; y < symboltable1.Length; y++) 
    { 
     for (int z = 0; z < text.Length; z++) 
     { 
      if (symboltable1[x,y] == text[z]) 
       listBox2.Items.Add(text[z]); 
      else 
       MessageBox.Show("poor"); 
     } 
    } 
} 

Answer 1

你的方法太慢O（N * M * L）（其中升是文本的长度，ñ & 米你的符号表的尺寸。）

将您的符号表转换为排序后的索引表会给你一个O（l * log（n * m）），并且使用散列表会给你一个几乎O（l）。

我实现了三个办法只是为了好玩：

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Threading.Tasks; 

namespace test 
{ 
    class Program 
    { 
     class IndexElement:IComparable<IndexElement> 
     { 
      public string value; 
      public int x; 
      public int y; 
      public IndexElement(string v,int x,int y) 
      { 
       this.value = v; 
       this.x = x; 
       this.y = y; 
      } 

      public int CompareTo(IndexElement other) 
      { 
       return value.CompareTo(other.value); 
      } 
     } 

     struct Position 
     { 
      public int x; 
      public int y; 
      public Position(int x, int y) 
      { 
       this.x = x; 
       this.y = y; 
      } 
     } 
     static void Main(string[] args) 
     { 
      string[,] symbols = new string[,] { { "if", "else" }, { "for", "foreach" }, { "while", "do" } }; 
      string[] text = new string[] { "for", "int", "in", "if", "then" }; 
      Dictionary<string, Position> dictionary = BuildDict(symbols); 
      IndexElement[] index = BuildIndex(symbols); 
      Console.WriteLine("Brute:"); 
      foreach (string s in CompareUsingBrute(text, symbols)) 
      { 
       Console.WriteLine(s); 
      } 
      Console.WriteLine("Dict:"); 
      foreach (string s in CompareUsingIndex(text, dictionary)) 
      { 
       Console.WriteLine(s); 
      } 
      Console.WriteLine("Indexing:"); 
      foreach (string s in CompareUsingDictionary(text, index)) 
      { 
       Console.WriteLine(s); 
      } 
      Console.ReadKey(); 
     } 

     private static List<string> CompareUsingBrute(string[] text, string[,] symbols) 
     { 
      List<string> res = new List<string>(); 
      for (int x = 0; x < symbols.GetLength(0); x++) 
      { 
       for (int y = 0; y < symbols.GetLength(1); y++) 
       { 
        for (int z = 0; z < text.Length; z++) 
        { 
         if (symbols[x, y] == text[z]) 
          res.Add(text[z]);       
        } 
       } 
      } 
      return res; 

     } 

     private static List<string> CompareUsingDictionary(string[] text, IndexElement[] index) 
     { 
      List<string> res = new List<string>(); 
      foreach (string s in text) 
      { 
       if (Array.BinarySearch<IndexElement>(index, new IndexElement(s, 0, 0)) >= 0) 
       { 
        res.Add(s); 
       } 
      } 
      return res; 
     } 

     private static IndexElement[] BuildIndex(string[,] symbols) 
     { 
      IndexElement[] res = new IndexElement[symbols.Length]; 
      int index = 0; 
      for (int i = 0; i < symbols.GetLength(0); i++) 
      { 
       for (int j = 0; j < symbols.GetLength(1); j++) 
       { 
        res[index] = new IndexElement(symbols[i, j], i, j); 
        index++; 
       } 

      } 
      Array.Sort(res); 
      return res; 
     } 

     private static List<string> CompareUsingIndex(string[] text, Dictionary<string, Position> dictionary) 
     { 
      List<string> res = new List<string>(); 
      foreach (string s in text) 
      { 
       Position p; 
       if (dictionary.TryGetValue(s,out p)) 
       { 
        res.Add(s); 
       } 
      } 
      return res; 
     } 

     private static Dictionary<string, Position> BuildDict(string[,] symbols) 
     { 
      Dictionary<string, Position> res = new Dictionary<string, Position>(); 
      for (int i = 0; i < symbols.GetLength(0); i++) 
      { 
       for (int j = 0; j < symbols.GetLength(1); j++) 
       { 
        res.Add(symbols[i, j], new Position(i, j)); 
       } 
      } 
      return res; 
     } 


    } 
} 

Answer 2

我想你的错误可能是在检查数组长度。
试试这个：

for (int x = 0; x < symboltable1.GetLength(0); x++) 
{ 
    for (int y = 0; y < symboltable1.GetLength(1); y++) 
    { 
     for (int z = 0; z < text.Length; z++) 
     { 
      if (symboltable1[x,y] == text[z]) 
       listBox2.Items.Add(text[z]); 
      else 
       MessageBox.Show("poor"); 
     } 
    } 
}