evalution of reverse polish formulas

1. examine each symbol in the reverse polish formula, starting at the extreme left untill you come to an operator.
2. write down the operator and the two operands immediately to its left on a piece of scratch paper.
3. erase the operator and the operands from the formula,creating a hole.
4. perform the operation on the operands and write the result in the hole.

• if the formula now consist of one value , that is the answer and the algorithm is finished otherwise goto step 1depicts the evaluation of a reverse polish formula. the order of the operator is the order in which they are actually evaluated.
  

• reverse polish is the ideal notation for evaluting formulas on a computer with stack.the formulas comsist os n symbols each one either a variable or an operator.the algorithm for evaluting a reverse polish formula using a stack is as follows.

• algorithm:

1. set k to 1
2. examine the kth symbol. of it is a variable, push it onto the stack. if it is an operator pop the top 2 iteams off the stack, perform the operation and push the result back onto the stack.
3. if k=n the algorithm terminates and the answer is on the stack; other wise add 1 to k and goto step 2.