programming-examples/c-sharp/Conversions/C# Program to Convert Infix to Postfix.cs

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2019-11-15 12:59:38 +01:00
/*
* C# Program to Convert Infix to Postfix
*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Infix
{
class Program
{
static bool convert(ref string infix, out string postfix)
{
int prio = 0;
postfix = "";
Stack<Char> s1 = new Stack<char>();
for (int i = 0; i < infix.Length; i++)
{
char ch = infix[i];
if (ch == '+' || ch == '-' || ch == '*' || ch == '/')
{
if (s1.Count <= 0)
s1.Push(ch);
else
{
if (s1.Peek() == '*' || s1.Peek() == '/')
prio = 1;
else
prio = 0;
if (prio == 1)
{
if (ch == '+' || ch == '-')
{
postfix += s1.Pop();
i--;
}
else
{
postfix += s1.Pop();
i--;
}
}
else
{
if (ch == '+' || ch == '-')
{
postfix += s1.Pop();
s1.Push(ch);
}
else
s1.Push(ch);
}
}
}
else
{
postfix += ch;
}
}
int len = s1.Count;
for (int j = 0; j < len; j++)
postfix += s1.Pop();
return true;
}
static void Main(string[] args)
{
string infix = "";
string postfix = "";
if (args.Length == 1)
{
infix = args[0];
convert(ref infix, out postfix);
System.Console.WriteLine("InFix :\t" + infix);
System.Console.WriteLine("PostFix:\t" + postfix);
}
else
{
infix = "a+b*c-d";
convert(ref infix, out postfix);
System.Console.WriteLine("InFix :\t" + infix);
System.Console.WriteLine("PostFix :\t" + postfix);
System.Console.WriteLine();
infix = "a+b*c-d/e*f";
convert(ref infix, out postfix);
System.Console.WriteLine("InFix :\t" + infix);
System.Console.WriteLine("PostFix :\t" + postfix);
System.Console.WriteLine();
infix = "a-b/c*d-e--f/h*i++j-/k";
convert(ref infix, out postfix);
System.Console.WriteLine("InFix :\t" + infix);
System.Console.WriteLine("PostFix :\t" + postfix);
System.Console.WriteLine();
Console.ReadLine();
}
}
}
}
/*
Infix : a+b*c-d
Postfix : abc*+d-
Infix : a+b*c-d/e*f
Postfix : abc*+de/f*-
Infix : a-b/c*d-e--f/h*I++j-/k
Postfix : abc/d*-e--fh/I*-=j=k/-