Infix equation solver c++ while loop stack

Im creating an infix problem solver and it crashes in the final while loop to finish the last part a of the equations.

I call a final while loop in main to solve whats left on the stack and it hangs there and if i pop the last element from the stack it will leave the loop and return the wrong answer.

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#include <iostream>
#include<stack>
#include<string>
#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <sstream>
using namespace std;
#define size 30
int count=0;
int count2=0;
int total=0;
stack< string > prob;
char equ[size];
char temp[10];
string oper;
string k;
char t[10];
int j=0;
char y;


   int solve(int f,int s, char o)
   {
  cout<<"f="<<f<<endl;
  cout<<"s="<<s<<endl;
  cout<<"o="<<o<<endl;
  int a;
  if (o== '*')//checks the operand stack for operator
  {
    cout << f << "*" << s << endl;
    a= f*s;
  }
  if (o == '/')//checks the operand stack for operator
  {
    cout << f << "/" << s << endl;
    if(s==0)
    {
      cout<<"Cant divide by 0"<<endl;
    }
    else
      a= f/s;
  }
  if (o == '+')//checks the operand stack for operator
  {
    cout << f << "+" << s << endl;
    a= f+s;
  }
  if (o == '-')//checks the operand stack for operator
  {
    cout << f << "-" << s << endl;
    a= f-s;
  }
  return a;
}



int covnum()
{
  int l,c;
  k=prob.top();
  for(int i=0;k[i]!='\n';i++)t[i]=k[i];
  return l=atoi(t);
}


char covchar()
{
  k=prob.top();
  for(int i=0;k[i]!='\n';i++)t[i]=k[i];
  return t[0];
}


void tostring(int a)
{
  stringstream out;
  out << a;
  oper = out.str();
}


void charstack(char op)
{
  oper=op;
  prob.push(oper);
}


void numstack(char n[])
{
  oper=n;
  prob.push(oper);
}

void setprob()
{
  int f,s;
  char o;
  char t;
  int a;
  int i;
  t=covchar();
  if(ispunct(t))
  {
    if(t=='(')
    {
      prob.pop();
    }
    if(t==')')
    {
      prob.pop();
    }
    else if(t=='+'||'-')
    {
      y=t;
      prob.pop();
    }
    else if(t=='/'||'*')
    {
      y=t;
      prob.pop();
    }
  }
  cout<<"y="<<y<<endl;
  i=covnum();
  cout<<"i="<<i<<endl;
  s=i;
  prob.pop();
  t=covchar();
  cout<<"t="<<t<<endl;
  if(ispunct(t))
  {
    o=t;
    prob.pop();
  }
  i=covnum();
  cout<<"i="<<i<<endl;
  f=i;
  prob.pop();
  t=covchar();
  if (t=='('||')')
  {
    prob.pop();
  }
  a=solve(f,s, o);
  tostring(a);
  prob.push(oper);
  cout<<"A="<<prob.top()<<endl;
}


void postfix()
{
  int a=0;
  char k;
  for(int i=0;equ[i]!='\0';i++)
  {
    if(isdigit(equ[i]))//checks array for number
    {
      temp[count]=equ[i];
      count++;
    }
    if(ispunct(equ[i]))//checks array for operator
    {
      if(count>0)//if the int input is done convert it to a string and push to stack
      {
        numstack(temp);
        count=0;//resets the counter
      }
      if(equ[i]==')')//if char equals the ')' then set up and solve that bracket
      {
        setprob();
        i++;//pushes i to the next thing in the array
        total++;
      }
      while(equ[i]==')')//if char equals the ')' then set up and solve that bracket
      {
        i++;
      }
      if(isdigit(equ[i]))//checks array for number
      {
        temp[count]=equ[i];
        count++;
      }
      if(ispunct(equ[i]))
      {
        if(equ[i]==')')//if char equals the ')' then set up and solve that bracket
        {
          i++;
        }
        charstack(equ[i]);
      }
      if(isdigit(equ[i]))//checks array for number
      {
        temp[count]=equ[i];
        count++;
      }
    }
  }
}



int main()
{
  int a=0;
  char o;
  int c=0;

  cout<<"Enter Equation: ";
  cin>>equ;
  postfix();
  while(!prob.empty())
  {
    setprob();
    a=covnum();
    cout<<a<<" <=="<<endl;
    prob.pop();
    cout<<prob.top()<<"<top before c"<<endl;
    c=covnum();
    a=solve(c,a,y);
  }
  cout<<"Final Awnser"<<a<<endl;
  system ("PAUSE");
  return 0;
}

Solution

I see a number of things which all likely contribute to the issue of it not working:

There are no error or bounds checking. I realize that this is homework and as such may have specific requirements/specifications which eliminate the need for some checks, but you still need some to ensure you are correctly parsing the input. What if you exceed the array size of equ/tmp/t? What if your stack is empty when you try to pop/top it?
There are a few if statements that look like else if (t == '+' || '-') which most likely doesn't do what you want them to. This expression is actually always true since '-' is non-zero and is converted to a true value. You probably want else if (t == '+' || t == '-').
As far as I can tell you seem to skip parsing or adding '(' to the stack which should make it impossible for you to actually evaluate the expression properly.
You have a while loop in the middle of postfix() which skips multiple ')' but doesn't do anything.
Your code is very hard to follow. Properly naming variables and functions and eliminating most of the globals (you don't actually need most of them) would help a great deal as would proper indentation and add a few spaces in expressions.
There are other minor issues not particularily worth mentioning. For example the covchar() and covnum() functions are much more complex than needed.

I've written a few postfix parsers over the years and I can't really follow what you are trying to do, which isn't to say the way you're trying is impossible but I would suggest re-examining at the base logic needed to parse the expression, particularly nested levels of brackets.