This is an Algorithm to evaluate of a postfix notation.
/* Reading of expression takes place from left to right */
1. Read the next element /* first element for the first time */
2. if element is operand
then push the element in the stack
3. if element is operator then
{
pop two operands from the stack
/* pop one operand in case of not operator */
evaluate the expression formed by the two operands and the operator push the result of the expression in the stack
}
4. if no-more-elements then pop the result
else
go to step 1