In Postfix expression operators are written after their operands. For example, the expressions given are in postfix notation A B C + * D /.
Point to consider
- Permitted operands: A,B,C,D means any real number is permitted.
- Permitted operators: +,-, *, /, ^(exponentiation)
- Blanks are permitted in the expression
- Parenthesis are permitted
Prefix and Postfix expressions can be evaluated faster in comparison to an infix expression because we donโt need to process any brackets or follow the operator precedence rule. In postfix and prefix expressions whichever operator comes before will be evaluated first, irrespective of its priority. Also, there are no brackets in these expressions. As long as we can guarantee that a valid prefix or postfix expression is used, it can be evaluated with correctness.
Algorithm to evaluate postfix expression
Step 1: If a character is an operand push it to Stack
Step 2: If the character is an operator
Pop two elements from the Stack.
Operate on these elements according to the operator, and push the result back to the Stack
Step 3: Step 1 and 2 will be repeated until the end has reached.
Step 4: The Result is stored at the top of the Stack,
return it
Step 5: End
Complexity of Postfix evaluation
The Postfix evaluation algorithm has linear complexity O(N). Since we scan the expression once and perform push and pop operations which take constant time.
Similar Reads
-
Multiplications of Two variable polynomial
Polynomial multiplication is a common operation in algebra, used in areas such as scientific computing, engineering simulations, and symbolic algebra… -
Subtraction of Two-Variable Polynomial in C
Polynomials with two variables are common in engineering, graphics, and scientific computation. While addition is frequently discussed, subtraction is equally… -
Explain the Addition of Two variable polynomial
Polynomials are fundamental in mathematics, and their use extends into computer science, engineering, physics, and more. While single-variable polynomials are… -
Reverses the Doubly Circular Linked List
Algorithm to Reverse a Doubly Circular Linked List Check if the List is Empty or Has Only One Node: If… -
Algorithm and Program in C to traverse Doubly Circular Linked List
A doubly circular linked list is a special type of linked list in which every node is connected to both… -
Polynomial representation Using Array
Polynomials are fundamental mathematical expressions used extensively in various fields. Representing them efficiently in programming is crucial for calculations and… -
Multiplication of Single Variable Polynomial : Algorithm and Program
Multiplication of single-variable polynomials is a fundamental operation in polynomial algebra. The process involves multiplying each term of one polynomial… -
Subtraction of Single variable Polynomial : Algorithm and Program
Subtracting single-variable polynomials involves reducing each corresponding term of the polynomials from each other. This process is similar to addition,… -
Addition of Single variable Polynomial : Program and Algorithm
The addition of single-variable polynomials is a fundamental concept in algebra, often encountered in mathematics and computer science. Let's break… -
Polynomial Representation Using Linked List
Polynomial representation using linked lists is a critical concept in computer science and mathematics. In this guide, we explore how…