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我是一名 C# 初学者，正在尝试读取二进制文件中的符号。我在 c# 中使用 ReadByte() 以唯一参数读取了这个二进制文件。通过这样做
using(var stream = new BinaryReader(System.IO.File.OpenRead(args[0])))
然后我做了
while (stream.BaseStream.Position < stream.BaseStream.Length)
{
int symbol = stream.ReadByte();
//And then i do my stuff
}
什么到这里一切都很好。
但我的下一步是制作通用类型的符号 "<T>" .所以我的算法是:
namespace Final
{
public Class A <T> where T: IComparable <T>
{
public Class Node
{
public T symbol; //This symbol has to be generic type because symbol may be int/long/uint etc. on 32/64 bit archtecture.
public Node next;
public int freq;
}
public Node Front;
public A(string[] args) //it's a constructor
{
Front = null;
using(var stream = new BinaryReader(System.IO.File.OpenRead(args[0])))
{
while (stream.BaseStream.Position < stream.BaseStream.Length)
{
Func < byte, T > converter = b = > new T(b);
byte byteValue = stream.ReadByte();
T processingValue = converter(byteValue); //here is the problem
Node pt, temp;
pt = Front;
while (pt != null)
{
if (pt.symbol == processingValue) //here is the problem
{
pt.freq++;
break;
}
temp = pt;
pt = pt.next;
}
}
}
stream.Close();
}
}
public class MyClass
{
public static void Main(string[] args)
{
A <T> ObjSym = new A <T> (args); //object creation
}
}
}
请注意有three class Class A , Class Node (包含符号)和 Class MyClass (包含我创建 object 的 main() 函数)并且在类 A 中我有我的 constructor .
现在我从昨天开始努力实现的是，我试图将“符号”作为通用数据类型，我的意思是符号可能是 int/uint/long等在 32/64 位架构上。另请注意，我正在阅读 Binary File 中的符号。 <强>在 sole argument 和二进制符号的形式(11010101 等)。
如果有人可以通过编辑算法来更正我的算法以实现我将符号设为 "generic" 的目标，我将不胜感激。 () 类型，从昨天开始我就被卡住了。非常感谢。
编辑:完整代码:
using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
namespace shekhar_final_version_Csharp
{
// public class Huffman<K> where K : IComparable<K>
public class Huffman < T > where T: struct, IComparable < T > , IEquatable < T >
{
public int data_size, length, i, is_there;
public class Node
{
public Node next, left, right;
public T symbol;
public int freq;
public int is_processed;
}
public Node front, rear;
///////////////////////////////////////////////
// public Huffman(string[] args)
public Huffman(string[] args, Func < byte[], int, T > converter)
{
front = null;
rear = null;
int size = Marshal.SizeOf(typeof (T));
// Console.WriteLine("Size: {0} ", size);
using(var stream = new BinaryReader(System.IO.File.OpenRead(args[0])))
{
while (stream.BaseStream.Position < stream.BaseStream.Length)
{
byte[] bytes = stream.ReadBytes(size);
T processingValue = converter(bytes, 0);
{
Node pt, temp;
bool is_there = false;
pt = front;
while (pt != null)
{
if (pt.symbol.Equals(processingValue))
{
pt.freq++;
is_there = true;
break;
}
temp = pt;
pt = pt.next;
}
if (is_there == false)
{
temp = new Node();
temp.symbol = processingValue;
temp.freq = 1;
temp.left = null;
temp.right = null;
temp.next = null;
temp.is_processed = 0;
if (front == null)
{
front = temp;
}
else
{
// Console.WriteLine("Symbol : {0} frequency is : {1}", pt.symbol, pt.freq);
temp.next = front;
front = temp;
}
}
}
Console.WriteLine("check1");
}
Console.WriteLine("check2");
stream.Close();
//////////////////////////////
}
}
public void Print_tree( Node treee)
{
Node pt = treee;
while (pt != null)
{
Console.WriteLine("Symbol : {0} frequency is : {1}", pt.symbol, pt.freq);
pt = pt.next;
}
}
/////////////////////////////
public Node find_two_smallest(ref Node pmin1, ref Node pmin2)
{
Node temp = front;
Node temp6 = front;
Node address = null;
Node min1;
min1 = new Node();
min1.freq = int.MaxValue;
Node min2;
min2 = new Node();
min2.freq = int.MaxValue;
while (temp != null)
{
if (temp.is_processed == 0)
{
if (temp.freq < min2.freq)
{
min1 = min2;
min2 = temp;
}
else if (temp.freq < min1.freq && temp.freq != min2.freq)
{
min1 = temp;
}
temp = temp.next;
}
else if (temp.is_processed == 1)
{
temp = temp.next;
}
}
pmin1 = min1;
pmin2 = min2;
// Below is the code to find the address of first minimum arriving on traversal of List which will be "front" for next execution.
while (temp6 != null)
{
if (temp6.freq == min1.freq || temp6.freq == min2.freq)
{
address = temp6;
break;
}
temp6 = temp6.next;
}
return address;
}
///////////////////////////////////////////////////////////////////
public int count_remaining()
{
int remaining = 0;
Node pt = front;
while (pt != null)
{
if (pt.is_processed == 0)
{
remaining += 1;
}
pt = pt.next;
}
return remaining;
}
////////////////////////////////////////////////////////////////////////////
public void huffman_node_processing()
{
Node temp, temp2;
temp2 = front;
while (temp2 != null)
{
if (temp2.next == null)
{
rear = temp2;
break;
}
temp2 = temp2.next;
}
int remaining;
int counter = 0;
remaining = count_remaining();
// You can un-comment these console.writeline(..); which are commented below if you want to see how the addition of nodes taking place(which nodes are added),
//I have commented it inorder to give direct and clear output.
while (front != rear)
{
if (counter == 0)
{
temp = new Node();
Console.WriteLine("first element1 {0} ", front.freq);
Console.WriteLine("second element1 {0} ", front.next.freq);
temp.freq = front.freq + front.next.freq;
front.is_processed = 1;
front.next.is_processed = 1;
temp.is_processed = 0;
temp.left = front;
temp.right = front.next;
temp.next = null;
rear.next = temp;
front = front.next.next;
Console.WriteLine("tempcheck1 {0} ", temp.freq);
rear = rear.next;
remaining = count_remaining();
if (remaining == 1)
{
break;
}
}
if (rear.freq == front.freq)
{
//Console.WriteLine("first element2 {0} ", front.freq);
//Console.WriteLine("second element2{0} ", front.next.freq);
temp = new Node();
temp.freq = front.freq + rear.freq;
rear.is_processed = 1;
front.is_processed = 1;
temp.is_processed = 0;
temp.left = front;
temp.right = rear;
temp.next = null;
rear.next = temp;
front = front.next;
//Console.WriteLine("temp check2 {0} ", front.freq);
rear = rear.next;
remaining = count_remaining();
if (remaining == 1)
{
break;
}
}
if (rear.freq > front.freq)
{
Node pmin1 = null;
Node pmin2 = null;
Node address = find_two_smallest(ref pmin1, ref pmin2);
temp = new Node();
Console.WriteLine("pmin1check3 {0} ", pmin1.freq);
Console.WriteLine("pmin2check3 {0} ", pmin2.freq);
temp.freq = pmin1.freq + pmin2.freq;
pmin1.is_processed = 1;
pmin2.is_processed = 1;
temp.is_processed = 0;
temp.left = pmin2;
temp.right = pmin1;
temp.next = null;
rear.next = temp;
front = address;
Console.WriteLine("tempcheck3 {0} ", temp.freq);
rear = rear.next;
remaining = count_remaining();
if (remaining == 1)
{
break;
}
}
if (rear.freq < front.freq)
{
Node pmin1 = null;
Node pmin2 = null;
Node address = find_two_smallest(ref pmin1, ref pmin2);
temp = new Node();
//Console.WriteLine("pmin1check4 {0} ", pmin1.freq);
//Console.WriteLine("pmin2check4 {0} ", pmin2.freq);
temp.freq = pmin1.freq + pmin2.freq;
pmin1.is_processed = 1;
pmin2.is_processed = 1;
temp.is_processed = 0;
temp.left = pmin2;
temp.right = pmin1;
temp.next = null;
rear.next = temp;
front = address;
//Console.WriteLine("tempcheck4 {0} ", temp.freq);
rear = rear.next;
remaining = count_remaining();
if (remaining == 1)
{
break;
}
}
counter++;
}
}
////////////////////////////////////////////
public void GenerateCode( Node parentNode, string code)
{
if (parentNode != null)
{
GenerateCode(parentNode.left, code + "0");
if (parentNode.left == null && parentNode.right == null)
Console.WriteLine("Symbol : " + parentNode.symbol + " frequency is : " + code);
GenerateCode(parentNode.right, code + "1");
}
}
}
public class MyClass
{
public static void Main(string[] args)
{
// Huffman<K> ObjSym = new Huffman<K>(args); //object creation
Huffman < long > ObjSym = new Huffman < long > (args, BitConverter.ToInt64);
Console.WriteLine("\nReading the Binary file......");
ObjSym.Print_tree(ObjSym.front);
ObjSym.huffman_node_processing();
Console.WriteLine("\nThe encoding of symbols are :");
ObjSym.GenerateCode(ObjSym.rear, "");
}
}
}
错误是:(为了调试，我尝试在构造函数中打印 check1 和 check2，但它只打印“check1”而不是“check2”)。请直到输出结束:
hp@ubuntu:~/Desktop/Internship_Xav/templatescplus$ mono test.exe toto.bin
check1
check1
check1
check1
check1
check1
check1
check1
check1
check1
check1
check1
check1
check1
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check1
Unhandled Exception: System.ArgumentException: Destination array is not long enough to copy all the items in the collection. Check array index and length.
at System.BitConverter.PutBytes (System.Byte* dst, System.Byte[] src, Int32 start_index, Int32 count) [0x00000] in <filename unknown>:0
at System.BitConverter.ToInt64 (System.Byte[] value, Int32 startIndex) [0x00000] in <filename unknown>:0
at shekhar_final_version_Csharp.Huffman`1[System.Int64]..ctor (System.String[] args, System.Func`3 converter) [0x00000] in <filename unknown>:0
at shekhar_final_version_Csharp.MyClass.Main (System.String[] args) [0x00000] in <filename unknown>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.ArgumentException: Destination array is not long enough to copy all the items in the collection. Check array index and length.
at System.BitConverter.PutBytes (System.Byte* dst, System.Byte[] src, Int32 start_index, Int32 count) [0x00000] in <filename unknown>:0
at System.BitConverter.ToInt64 (System.Byte[] value, Int32 startIndex) [0x00000] in <filename unknown>:0
at shekhar_final_version_Csharp.Huffman`1[System.Int64]..ctor (System.String[] args, System.Func`3 converter) [0x00000] in <filename unknown>:0
at shekhar_final_version_Csharp.MyClass.Main (System.String[] args) [0x00000] in <filename unknown>:0
hp@ubuntu:~/Desktop/Internship_Xav/templatescplus$
最佳答案
您必须将转换函数和数字类型的大小传递到 A 的构造函数中:
public A(string[] args, int size, Func<byte[], int, T> converter) { ... }
A<long> ObjSym = new A<long>(args, sizeof(long), BitConverter.ToInt64)
您可以使用 Marshal.SizeOf 而不是直接传递大小:
int size = Marshal.SizeOf(typeof(T));
然后就可以从阅读器中读取需要的字节数并进行转换了:
byte[] bytes = stream.ReadBytes(size);
T processingValue = converter(bytes, 0);
您可以使用 Equals 检查符号:
if (pt.symbol.Equals(processingValue))
如果进一步约束类型参数以实现 IEquatable<T>，则可以在相等性检查期间避免装箱:
public class A<T> where T : struct, IComparable <T>, IEquatable<T>
{
public class Node
{
public T symbol;
public Node next;
public int freq;
}
public Node Front;
public A(string[] args, Func<byte[], int, T> converter)
{
int size = Marshal.SizeOf(typeof(T));
Front = null;
using(var stream = new BinaryReader(System.IO.File.OpenRead(args[0])))
{
while (stream.BaseStream.Position < stream.BaseStream.Length)
{
byte[] bytes = stream.ReadBytes(size);
T processingValue = converter(bytes, 0);
Node pt, temp;
pt = Front;
while (pt != null)
{
if (pt.symbol.Equals(processingValue))
{
pt.freq++;
break;
}
temp = pt;
pt = pt.next;
}
}
}
}
}
关于c# - 使用 ReadByte() 读取泛型类型，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22544131/
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