LeetCode - Easy - 193. Valid Phone Numbers-蒲公英云

LeetCode - Easy - 193. Valid Phone Numbers

傷城~ 2022-12-30 08:16 227阅读 0赞

Topic

Bash

Description

https://leetcode.com/problems/valid-phone-numbers/

Given a text file file.txt that contains list of phone numbers (one per line), write a one liner bash script to print all valid phone numbers.

You may assume that a valid phone number must appear in one of the following two formats: (xxx) xxx-xxxx or xxx-xxx-xxxx. (x means a digit)

You may also assume each line in the text file must not contain leading or trailing white spaces.

Example:

Assume that file.txt has the following content:

987-123-4567
123 456 7890
(123) 456-7890

Your script should output the following valid phone numbers:

987-123-4567
(123) 456-7890

Analysis

In Bash, we use \ to escape next one trailing character;
^ is used to denote the beginning of a line
$ is used to denote the end of a line
{M} is used to denote to match exactly M times of the previous occurence/regex
(...) is used to group pattern/regex together

Submission

grep -e '\(^[0-9]\{3\}-[0-9]\{3\}-[0-9]\{4\}$\)' -e '\(^([0-9]\{3\})[ ]\{1\}[0-9]\{3\}-\([0-9]\{4\}\)$\)'  file.txt
grep -e "^\([0-9]\{3\}-\|([0-9]\{3\}) \)[0-9]\{3\}-[0-9]\{4\}$" file.txt