Postfix to Evaluation (any digit)

#include <stdio.h>
#include <iostream>
#include <stack>
using namespace std;

int main()
{
    char postfix[100] = {'\0'};
    int Digit1[20], Digit2[20];
    int i=0,j=0,k=0,var1=0,var2=0,result=0,Count1=0,Count2=0,p=1,x=0,Count3=0;
    cout << "Input Postfix Expression: ";
    gets(postfix);
    cout << "Input expression is..." <<endl;
    puts(postfix);
    stack <int> myStack;
    for(i=0;postfix[i] != '\0'; i++)
    {
        if(postfix[i]==',')
        {
            Count3++;
        }
    }
    for(i=0; postfix[i]!='\0'; i++)
    {
        if (postfix[i] != '+' && postfix[i] != '-' && postfix[i] != '*' && postfix[i] != '/')
        {
            if(postfix[i] != ',')
            {
                myStack.push(postfix[i]-'0');
            }
            else
            {
                myStack.push(postfix[i]);
            }

        }
        else
        {
            if(myStack.top()==',')
            {
               myStack.pop();
            }
            var1 =0;
            Count1=0;
            if(myStack.top()>9)
            {
                var1= myStack.top();
                myStack.pop();
                x=1;
            }
            else
            {
                for(j=0; myStack.top() != ','; j++)
                {
                    Digit1[j] = myStack.top();
                    myStack.pop();
                    Count1++;
                }
                p=1;
                for(j=0; j<Count1; j++)
                {
                    var1 =  var1 +(Digit1[j] * p);
                    p = p*10;
                }
            }

            if(myStack.top()==',')
            {
               myStack.pop();
            }
            var2=0;
            Count2=0;
            if(Count3>2)
            {
                if(x==1)
                {
                    for(k=0; !myStack.empty(); k++)
                    {
                        Digit2[k] = myStack.top();
                        if(!myStack.empty())
                        {
                            myStack.pop();
                        }
                        Count2++;
                    }
                }
                else
                {
                    for(k=0; myStack.top() != ',' && !myStack.empty(); k++)
                    {
                        Digit2[k] = myStack.top();
                        if(!myStack.empty())
                        {
                            myStack.pop();
                        }
                        Count2++;
                    }
                }
            }
            else
            {
                for(k=0; !myStack.empty(); k++)
                {
                    Digit2[k] = myStack.top();
                    if(!myStack.empty())
                    {
                        myStack.pop();
                    }
                    Count2++;
                }
            }
            p=1;
            for(k=0; k<Count2; k++)
            {
                var2 =  var2 +(Digit2[k] * p);
                p = p*10;

            }

            if(postfix[i] == '+')
            {
                result = var1 + var2;
                myStack.push(result);
                result = 0;
            }
            else if(postfix[i] == '-')
            {
                result = var2 - var1;
                myStack.push(result);
                result = 0;
            }
            else if(postfix[i] == '*')
            {
                result = var1 * var2;
                myStack.push(result);
                result = 0;
            }
            else if(postfix[i] == '/')
            {
                result = var2 / var1;
                myStack.push(result);
                result = 0;
            }

        }

    }
    result = myStack.top();
    cout << "\n" << "Result is: " << result << endl;

    return 0;
}