see a class that has a string here is a function for that class that remove space.
Code:
void clc::remove_spcae()
{ 
	cout<<"string inputted by user is "<<eqn<<endl;
	int i(0);
	do
	{
		if(eqn[i]==' ')
		{
			for(int j=i+1;eqn[j]!='\0';j++)
			{
				if(eqn[j]==' ')
						cout<<"";
				else
				{
					if(eqn[j]=='\0')
                                        {
                                             eqn[i]=eqn[j];                                 
					     break;
                                         }
					eqn[i]=eqn[j];
					eqn[j]=' ';
					this->eatspcae();
				}
			}
		}
		i++;
	}
	while(eqn[i]!='\0');
	cout<<"newer string is "<<this->eqn<<endl;
}
some special i see in this function is that it calls itself even after printing last line that is
Code:
cout<<"newer string is "<<this->eqn<<endl;
it should call irself from inside function not if it came outside do while loop.

if it not do so then it will work correctly.
as well as it hangs just before end.
after running it twice my CPU usage is goes to70%(and not going down) which is usually 5 % to 15% are these things linked to each other.
thnk's to all answerer.