أقحم لتحويل لواحق
https://stackoverflow.com/questions/1438030
-
08-07-2019 - |
italiano
english
français
española
中国
日本の
العربية
Deutsch
한국어
Português
Russianسؤال
ولقد تم العمل على هذا أقحم لواحق / بوليس تحويل التدوين. على الرغم من أنني لا أشعر الحل هو كاف. على وجه التحديد ي (تحرير: تسمى الآن رقم قياسي). متغير يتم التنصت لي
هل اللاعبين لديه أي اقتراحات؟ أو ربما هناك طريقة أفضل بكثير لتحقيق ذلك؟ أو أقوم فقط تقلق كثيرا؟
public static string[] InfixToPostfix(string[] infixArray)
{
var stack = new Stack<string>();
var postfix = new string[infixArray.Length];
int index = 0;
string st;
for (int i = 0; i < infixArray.Length; i++)
{
if (!(MyMath.MathOperators.Contains(infixArray[i])))
{
postfix[index] = infixArray[i];
index++;
}
else
{
if (infixArray[i].Equals("("))
{
stack.Push("(");
}
else if (infixArray[i].Equals(")"))
{
st = stack.Pop();
while (!(st.Equals("(")))
{
postfix[index] = st;
index++;
st = stack.Pop();
}
}
else
{
while (stack.Count > 0)
{
st = stack.Pop();
if (RegnePrioritet(st) >= RegnePrioritet(infixArray[i]))
{
postfix[index] = st;
index++;
}
else
{
stack.Push(st);
break;
}
}
stack.Push(infixArray[i]);
}
}
}
while (stack.Count > 0)
{
postfix[index] = stack.Pop();
index++;
}
return postfix.TakeWhile(item => item != null).ToArray();
}
المحلول
إذا قمت باستبدال array من قبل Stack<string>، لم يكن لديك لتتبع حيث كنت مع المتغير index.
وبعد ذلك يمكنك العودة نتيجة مع postfixStack.ToArray()
وتنفيذ بلدي:
public static string[] InfixToPostfix( string[] infixArray )
{
var stack = new Stack<string>();
var postfix = new Stack<string>();
string st;
for ( int i = 0 ; i < infixArray.Length ; i++ )
{
if ( !( "()*/+-".Contains( infixArray[ i ] ) ) )
{
postfix.Push(infixArray[i]);
}
else
{
if ( infixArray[ i ].Equals( "(" ) )
{
stack.Push( "(" );
}
else if ( infixArray[ i ].Equals( ")" ) )
{
st = stack.Pop();
while ( !( st.Equals( "(" ) ) )
{
postfix.Push( st );
st = stack.Pop();
}
}
else
{
while ( stack.Count > 0 )
{
st = stack.Pop();
if ( RegnePrioritet( st ) >= RegnePrioritet( infixArray[ i ] ) )
{
postfix.Push(st);
}
else
{
stack.Push( st );
break;
}
}
stack.Push( infixArray[ i ] );
}
}
}
while ( stack.Count > 0 )
{
postfix.Push(stack.Pop());
}
return postfix.Reverse().ToArray();
}
نصائح أخرى
وهنا هو تطبيق بسيط للغاية (أرقام أو الأقواس و+ - / * شركات فقط) للحصول على معلومات حول ويكيبيديا حول أقحم، لواحق وخوارزمية السحب يارد. يمكن neatened ارتفاعا وتحسين جرا، والتي سأفعل للعمل بلدي، ولكن أنا نشر هنا قبل أن تخصيصه إلى ما بعد الاعتراف:
using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
namespace Infix_to_Postfix
{
#region enums
enum TokenTypes
{
Operator,
Number,
Parenthesis
}
enum Associativenesses
{
Left,
Right
}
enum OperatorTypes { Plus, Minus, Multiply, Divide, Equals, Exclamation, Modulus }
enum ParenthesisTypes { Open, Close }
#endregion
#region classes
public class Token { }
class Operator : Token
{
public OperatorTypes OperatorType { get; set; }
public Operator(OperatorTypes operatorType) { OperatorType = operatorType; }
public int Precedence
{
get
{
switch (this.OperatorType)
{
case OperatorTypes.Exclamation:
return 4;
case OperatorTypes.Multiply:
case OperatorTypes.Divide:
case OperatorTypes.Modulus:
return 3;
case OperatorTypes.Plus:
case OperatorTypes.Minus:
return 2;
case OperatorTypes.Equals:
return 1;
default:
throw new Exception("Invalid Operator Type for Precedence get");
}
}
}
public Associativenesses Associativeness
{
get
{
switch (this.OperatorType)
{
case OperatorTypes.Equals:
case OperatorTypes.Exclamation:
return Associativenesses.Right;
case OperatorTypes.Plus:
case OperatorTypes.Minus:
case OperatorTypes.Multiply:
case OperatorTypes.Divide:
case OperatorTypes.Modulus:
return Associativenesses.Left;
default:
throw new Exception("Invalid Operator Type for Associativeness get");
}
}
}
public override string ToString()
{
switch (OperatorType)
{
case OperatorTypes.Plus: return "+";
case OperatorTypes.Minus: return "-";
case OperatorTypes.Multiply: return "*";
case OperatorTypes.Divide: return "/";
case OperatorTypes.Equals: return "=";
case OperatorTypes.Exclamation: return "!";
case OperatorTypes.Modulus: return "%";
default: return null;
}
}
public static OperatorTypes? GetOperatorType(string operatorValue)
{
switch (operatorValue)
{
case "+": return OperatorTypes.Plus;
case "-": return OperatorTypes.Minus;
case "*": return OperatorTypes.Multiply;
case "/": return OperatorTypes.Divide;
case "=": return OperatorTypes.Equals;
case "!": return OperatorTypes.Exclamation;
case "%": return OperatorTypes.Modulus;
default: return null;
}
}
}
class Parenthesis : Token
{
public ParenthesisTypes ParenthesisType { get; set; }
public Parenthesis(ParenthesisTypes parenthesisType) { ParenthesisType = parenthesisType; }
public override string ToString() { if (ParenthesisType == ParenthesisTypes.Open) return "("; else return ")"; }
public static ParenthesisTypes? GetParenthesisType(string parenthesisValue)
{
switch (parenthesisValue)
{
case "(": return ParenthesisTypes.Open;
case ")": return ParenthesisTypes.Close;
default: return null;
}
}
}
class Numeric : Token
{
public decimal Value { get; set; }
public Numeric(decimal value) { Value = value; }
public override string ToString() { return Value.ToString(); }
}
public class Formula
{
public Stack<Token> InfixTokens { get; set; }
public Stack<Token> PostfixTokens { get; set; }
public string RawFormula { get; set; }
public Formula(string rawFormula)
{
// store the raw formula
RawFormula = rawFormula;
InfixTokens = new Stack<Token>();
PostfixTokens = new Stack<Token>();
#region generate the InFix Stack
Stack<Token> tokens = new Stack<Token>();
string store = "";
// parse the formula into a stack of tokens
while (rawFormula.Length > 0)
{
string ThisChar = rawFormula.Substring(0, 1);
if (Regex.IsMatch(ThisChar, "[0-9\\.]"))
{
// a numeric char, so store it until the number is reached
store += ThisChar;
}
else if (Operator.GetOperatorType(ThisChar) != null)
{
// a value is stored, so add it to the stack before processing the operator
if (store != "")
{
tokens.Push(new Numeric(Convert.ToDecimal(store)));
store = "";
}
tokens.Push(new Operator((OperatorTypes)Operator.GetOperatorType(ThisChar)));
}
else if (Parenthesis.GetParenthesisType(ThisChar)!=null)
{
// a value is stored, so add it to the stack before processing the parenthesis
if (store != "")
{
tokens.Push(new Numeric(Convert.ToDecimal(store)));
store = "";
}
tokens.Push(new Parenthesis((ParenthesisTypes)Parenthesis.GetParenthesisType(ThisChar)));
}
else
{
// ignore blanks (unless between to numbers)
if (!(ThisChar == " " && !(store != "" && Regex.IsMatch(rawFormula.Substring(1, 1), "[0-9\\.]"))))
{
throw new Exception("Invalid character in Formula: " + ThisChar);
}
}
// move to the next position
rawFormula = rawFormula.Substring(1);
}
// if there is still something in the numeric store, add it to the stack
if (store != "")
{
tokens.Push(new Numeric(Convert.ToDecimal(store)));
}
// reverse the stack
Stack<Token> reversedStack = new Stack<Token>();
while (tokens.Count > 0) reversedStack.Push(tokens.Pop());
// store in the Tokens property
InfixTokens = reversedStack;
#endregion
#region generate the PostFix Stack
// get a reversed copy of the tokens
Stack<Token> infixTokens = new Stack<Token>(InfixTokens);
Stack<Token> InFixStack = new Stack<Token>();
while (infixTokens.Count > 0) InFixStack.Push(infixTokens.Pop());
// new stacks
Stack<Token> output = new Stack<Token>();
Stack<Token> operators = new Stack<Token>();
while (InFixStack.Count > 0)
{
Token currentToken = InFixStack.Pop();
// if it's an operator
if (currentToken.GetType() == typeof(Operator))
{
// move precedent operators to output
while (operators.Count > 0 && operators.Peek().GetType() == typeof(Operator))
{
Operator currentOperator = (Operator)currentToken;
Operator nextOperator = (Operator)operators.Peek();
if ((currentOperator.Associativeness == Associativenesses.Left && currentOperator.Precedence <= nextOperator.Precedence)
|| (currentOperator.Associativeness == Associativenesses.Right && currentOperator.Precedence < nextOperator.Precedence))
{
output.Push(operators.Pop());
}
else
{
break;
}
}
// add to operators
operators.Push(currentToken);
}
// if it's a bracket
else if (currentToken.GetType() == typeof(Parenthesis))
{
switch (((Parenthesis)currentToken).ParenthesisType)
{
// if it's an opening bracket, add it to operators
case ParenthesisTypes.Open:
operators.Push(currentToken);
break;
// if it's a closing bracket
case ParenthesisTypes.Close:
// shift operators in between opening to output
while (operators.Count > 0)
{
Token nextOperator = operators.Peek();
if (nextOperator.GetType() == typeof(Parenthesis) && ((Parenthesis)nextOperator).ParenthesisType == ParenthesisTypes.Open) break;
output.Push(operators.Pop());
}
// add to operators
operators.Pop();
break;
}
}
// if it's numeric, add to output
else if (currentToken.GetType() == typeof(Numeric))
{
output.Push(currentToken);
}
}
// for all remaining operators, move to output
while (operators.Count > 0)
{
output.Push(operators.Pop());
}
// reverse the stack
reversedStack = new Stack<Token>();
while (output.Count > 0) reversedStack.Push(output.Pop());
// store in the Tokens property
PostfixTokens = reversedStack;
#endregion
}
public decimal Calculate()
{
Stack<Numeric> EvaluationStack = new Stack<Numeric>();
// get a reversed copy of the tokens
Stack<Token> postFixStack = new Stack<Token>(PostfixTokens);
Stack<Token> PostFixStack = new Stack<Token>();
while (postFixStack.Count > 0) PostFixStack.Push(postFixStack.Pop());
while (PostFixStack.Count > 0)
{
Token currentToken = PostFixStack.Pop();
if (currentToken.GetType() == typeof(Numeric))
{
EvaluationStack.Push((Numeric)currentToken);
}
else if (currentToken.GetType() == typeof(Operator))
{
Operator currentOperator = (Operator)currentToken;
if (currentOperator.OperatorType == OperatorTypes.Plus
|| currentOperator.OperatorType == OperatorTypes.Minus
|| currentOperator.OperatorType == OperatorTypes.Multiply
|| currentOperator.OperatorType == OperatorTypes.Divide)
{
decimal FirstValue = EvaluationStack.Pop().Value;
decimal SecondValue = EvaluationStack.Pop().Value;
decimal Result;
if (currentOperator.OperatorType == OperatorTypes.Plus)
{
Result = SecondValue + FirstValue;
}
else if (currentOperator.OperatorType == OperatorTypes.Minus)
{
Result = SecondValue - FirstValue;
}
else if (currentOperator.OperatorType == OperatorTypes.Divide)
{
Result = SecondValue / FirstValue;
}
else if (currentOperator.OperatorType == OperatorTypes.Multiply)
{
Result = SecondValue * FirstValue;
}
else
{
throw new Exception("Unhandled operator in Formula.Calculate()");
}
EvaluationStack.Push(new Numeric(Result));
Console.WriteLine("EVAL: " + SecondValue.ToString() + " " + currentOperator.ToString() + " " + FirstValue.ToString() + " = " + Result.ToString());
}
}
else
{
throw new Exception("Unexpected Token type in Formula.Calculate");
}
}
if (EvaluationStack.Count != 1)
{
throw new Exception("Unexpected number of Tokens in Formula.Calculate");
}
return EvaluationStack.Peek().Value;
}
}
#endregion
class Program
{
static void Main(string[] args)
{
try
{
string Equation = "";
Equation = "1+2+3";
Equation = "(((12.7+2)/3)-10)*(32+(3*5))";
Equation = "5 + ((1 + 2) * 4) - 3";
Equation = "1 + (3 * 4) - 3";
Equation = "5+8-(2*2)";
Equation = "10/2+3/2*4-2+4*3/4-9";
Equation = "6/2*4";
Equation = "3 + 4 * 2 / ( 1 - 5 ) ";
Console.WriteLine("EQUATION: " + Equation);
Formula formula = new Formula(Equation);
Console.WriteLine("INFIX: " + String.Join(" ", formula.InfixTokens));
Console.WriteLine("POSTFIX: " + String.Join(" ", formula.PostfixTokens));
decimal Result = formula.Calculate();
Console.WriteLine("RESULT: " + Result.ToString());
}
catch (Exception Err)
{
Console.WriteLine("ERROR: " + Err.Message);
}
Console.ReadLine();
}
}
}
وجرب هذا. فإنه يأخذ مني بعض الوقت لرمز هذا ولكن يعمل لكل الأمثلة التي وجدت على الإنترنت.
public void evaluate(Stack stk){
Stack output= new Stack();
Stack operators= new Stack();
while(!stk.isEmpty()){
String str = stk.get(0).toString();
str = str.replace("\\s", "");
stk.removeElementAt(0);
if(isNumerical(str)){
output.push(str);
}
else if(!isNumerical(str)){
char c = str.charAt(0);
System.out.println(c);
if(c=='('){
operators.push(c);
}
else if(c==')'){
char x= operators.pop().toString().charAt(0);
while(x!='('){
System.out.println("That line excecuted and removed the char "+x);
output.push(x);
x=operators.pop().toString().charAt(0);
}
}
else if(!output.isEmpty() && !operators.isEmpty()){
System.out.println("Printme");
char s= operators.lastElement().toString().charAt(0);
System.out.println(s);
System.out.println(c);
if(precedenceNum(s)>=precedenceNum(c)){
String op =operators.pop().toString();
output.push(op);
operators.push(str);
}
else{
operators.push(str);
}
}
else if(operators.isEmpty()){
operators.push(str);
}
System.out.println(operators);
}
}
while(!operators.isEmpty()){
output.push(operators.pop());
}
System.out.println(output);
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace infix_to_postfix
{
class Program
{
static void Main(string[] args)
{
int i = new int();
Console.WriteLine("Enter the length of notation:");
//bool extra = new bool();
//do {
// try
// {
i = Convert.ToInt32(Console.ReadLine()); //enter the length of notation
//}
//catch
//{
//Console.WriteLine("Please Get Out");
// extra = false;
// }
//} while (extra== false);
string[] infix = new string[i];
string[] postfix = new string[i];
string[] temp = new string[i];
Console.WriteLine("Enter values");
int l = 0;
for ( l = 0; l < i; l++)
{
infix[l] = Console.ReadLine();
}
int x = 0;
Console.Write("Infix:");
for ( x = 0; x < i; x++)
{
Console.Write( infix[x]);
}
// removing paranthesis
for(int z=i-1;z>=0;z--)
{
int c = z;
if (infix[z] == "(")
{
infix[z] = null;
}
if (infix[z] == "+" || infix[z] == "*" || infix[z] == "/" || infix[z] == "-")
{
do
{
c++;
if (infix[c] == ")")
{
infix[c] = infix[z];
infix[z] = null;
break;
}
}
while (c < i) ;
}
}
//filling up
int lagao = 0;
for(int v=0;v<i;v++)
{
if(infix[v]!=null )
{
postfix[lagao] = infix[v];
lagao++;
}
}
int p = 0;
Console.Write("postfix:");
for (p = 0; p < i; p++)
{
Console.Write(postfix[p]);
}
//int s = new int();
//switch(s)
//{
// case 1:
// break;
// case 2:
// break;
// case 3:
// break;
// default:
// break;
//}
Console.ReadKey();
}
}
}
لا تنتمي إلى StackOverflow
