https://github.com/jtwebman/infix-to-prefix

Function that given an infix arithmetic expression, outputs a prefix version
https://github.com/jtwebman/infix-to-prefix

Last synced: 11 days ago
JSON representation

Function that given an infix arithmetic expression, outputs a prefix version

• Host: GitHub
• URL: https://github.com/jtwebman/infix-to-prefix
• Owner: jtwebman
• Created: 2015-12-18T18:01:40.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2015-12-18T19:12:56.000Z (almost 9 years ago)
• Last Synced: 2024-08-08T19:43:07.653Z (3 months ago)
• Language: JavaScript
• Size: 2.93 KB
• Stars: 1
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# Infix Arithmetic Expression Problem

I have gotten this question in an interview before and wanted to work through

it to get it right. Let me know if you find a better way!

## Question

Write a function that given an infix arithmetic expression, outputs a prefix version (the output order is unimportant as long as it evaluates to the same result).

For example:

3                becomes     3

1 + 2            becomes     (+ 1 2)

3 + 1 - 2        becomes     (- (+ 3 1) 2)

1 + 2 * 5        becomes     (+ 1 (* 2 5))

2 + 3 * 4 / 5    becomes     (+ 2 (/ (* 3 4) 5)

1 + 3 * 4 - 8    becomes     (- (+ 1 (* 3 4) 8)

Quick notes:

- Parentheses in the output are not important - they are only in the examples for readability.

- You can assume input and output are given as arrays of strings, e.g. [“3”, “+”, “1”, … etc.]

- You can assume there are convenience functions such as isOperator.

## To Test

```bash

npm install infix-to-prefix

npm test

```

[Here is the actual code](function.js)

[Here are the tests](test/function_tests.js)