Write an algorithm to calculate a postfix expression.  Execute your algorithm using the given postfix expression as your input : a b + c d +*f ↑ .

To evaluate a postfix expression by using the given values:

clear the stack

symb  = next input character while(not end of input)

{

if (symb is an operand)

push onto the stack;

else

{

pop two operands from the stack;

result=op1 symb op2;

push result onto the stack;

}

symb = next input character;

}

return (pop (stack));

The input postfix expression is given as:- ab+cd+*f^

Symb                 Stack                                          Evaluation a    a

b                    a b

+                   pop a and b                                 (a + b) Push (a + b)

c                    (a + b) c

d                   (a + b) c d

+                   pop c and d                                 (c + d) Push (c + d)

*                    pop (a + b) and (c + d)                (a + b) * (c + d)

f                    (a + b) * (c + d) f

^                    pop (a + b) * (c + d) and f           (a + b) * (c + d) ^ f

The result of evaluation is ((a + b) * (c + d)) ^ f

Posted Date: 7/9/2012 10:03:51 PM | Location : United States

Ask an Expert

Related Discussions:- Postfix expression algorithm, Assignment Help, Ask Question on Postfix expression algorithm, Get Answer, Expert's Help, Postfix expression algorithm Discussions

Write discussion on Postfix expression algorithm
Your posts are moderated

Write your message here..

Related Questions

Sorting algorithm is best if the list is already sorted, Which sorting algo... Which sorting algorithm is best if the list is already sorted? Why? Insertion sort as there is no movement of data if the list is already sorted and complexity is of the order

Define binary search technique, Binary search technique:-  This techniq... Binary search technique:-  This technique is applied to an ordered list where elements are arranged either in ascending order or descending order. The array is separated into t

Hasing and indexing, differentiate between indexing and hashing in file org... differentiate between indexing and hashing in file organization

Time required to delete a node x from a doubly linked list, The time needed... The time needed to delete a node x from a doubly linked list having n nodes is O (1)

Internal sorting, In internal sorting, all of the data to be sorted is obta... In internal sorting, all of the data to be sorted is obtainable in the high speed main memory of the computer. We will learn the methods of internal sorting which are following:

Different ways for representing s graph, W h at are the different ways by... W h at are the different ways by which we can represent graph?  Represent the graph drawn below using those ways.     T he d iff e r e nt w a y s by

Determine the comparison of gouraud and phong shading, Comparison of Gourau... Comparison of Gouraud and Phong Shading Phong shading requires more calculations, but produces better results for specular reflection than Gouraud shading in the form of more r

Tree, application of threaded binary treee application of threaded binary treee

Insertion sort, Data array A has data series from 1,000,000 to 1 with step ... Data array A has data series from 1,000,000 to 1 with step size 1, which is in perfect decreasing order. Data array B has data series from 1 to 1,000,000, which is in random order.

Which data structure is used for implementing recursion, Which data structu... Which data structure is used for implementing recursion Stack.