Postfix Expression Evaluation Problem Statement

Given a postfix expression, your task is to evaluate the expression. The operator will appear in the expression after the operands. The output for each expression should be the result modulo (109+7). Use modular division when necessary.

Example:

Explanation:
Infix expression: A + B * C - D
Postfix expression: A B + C D - *

Input:

The first line contains an integer ‘T’ representing the number of test cases.
Each of the next ‘T’ lines contains one postfix expression.

Output:

For each test case, print the integer result of evaluating the given postfix expression.

Constraints:

  • The first line of input contains an integer ‘T’ such that 1 ≤ T ≤ 100
  • Each postfix expression has a length ‘N’ such that 1 ≤ N ≤ 103
  • The operands in the expression are represented by integers ‘NUM’ such that 1 ≤ NUM ≤ 100
  • Operators include: '*', '/', '+', '-'
  • Operators and operands are separated by a space
  • No brackets are present in the postfix expression

Note:

You do not need to print the expected output; just implement the function.
AnswerBot
4mo

Evaluate postfix expressions by applying operators after operands. Return result modulo (10^9+7).

  • Iterate through each character in the postfix expression

  • If character is an operand, push it onto the st...read more

Help your peers!
Select
Add answer anonymously...

Amazon Software Developer interview questions & answers

A Software Developer was asked 1mo agoQ. Could you describe the process for designing a data structure that allows for al...read more
A Software Developer was asked 1mo agoQ. What is MySQL?
A Software Developer was asked 1mo agoQ. What is Java?

Popular interview questions of Software Developer

A Software Developer was asked 1mo agoQ1. Could you describe the process for designing a data structure that allows for al...read more
A Software Developer was asked 1mo agoQ2. What is MySQL?
A Software Developer was asked 1mo agoQ3. What is Java?

Top HR questions asked in Amazon Software Developer

A Software Developer was asked 1mo agoQ1. Tell me about a time you had to get to the root cause of a problem
A Software Developer was asked 5mo agoQ2. What are the short-term and long-term goals for the team or organization?
A Software Developer was asked 5mo agoQ3. Why do you want to work at Amazon?
Amazon Software Developer Interview Questions
Stay ahead in your career. Get AmbitionBox app
play-icon
play-icon
qr-code
Trusted by over 1.5 Crore job seekers to find their right fit company
80 L+

Reviews

10L+

Interviews

4 Cr+

Salaries

1.5 Cr+

Users

Contribute to help millions

Made with ❤️ in India. Trademarks belong to their respective owners. All rights reserved © 2025 Info Edge (India) Ltd.

Follow Us
  • Youtube
  • Instagram
  • LinkedIn
  • Facebook
  • Twitter
Profile Image
Hello, Guest
AmbitionBox Employee Choice Awards 2025
Winners announced!
awards-icon
Contribute to help millions!
Write a review
Write a review
Share interview
Share interview
Contribute salary
Contribute salary
Add office photos
Add office photos
Add office benefits
Add office benefits