/* The code uses a simple two-stack algorithm. See
* http://www.onthenet.com.au/~grahamis/int2008/week02/lect02.html
* for a detailed explaination of the infix-to-postfix algorithm on which
* this is based (this code differs in that it applies operators immediately
* to the stack instead of adding them to a queue to end up with an
* expression). */
/* The code uses a simple two-stack algorithm. See
* http://www.onthenet.com.au/~grahamis/int2008/week02/lect02.html
* for a detailed explaination of the infix-to-postfix algorithm on which
* this is based (this code differs in that it applies operators immediately
* to the stack instead of adding them to a queue to end up with an
* expression). */