How hard is LeetCode 193. Valid Phone Numbers?

LeetCode 193. Valid Phone Numbers is rated Easy on LeetCode.

What topics does LeetCode 193. Valid Phone Numbers cover?

LeetCode 193. Valid Phone Numbers is tagged Shell on LeetCode.

Valid Phone Numbers — LeetCode 193 Python Solution

EasyShell

Problem: #193
Reading time: 2 min
Source: leetcode.com

The problem

Given a text file file.txt that contains a 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.

Example

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

Python solution

Python

import re

def print_valid_numbers(path: str = "file.txt") -> None:
    pattern = re.compile(r"^(\(\d{3}\) |\d{3}-)\d{3}-\d{4}$")
    with open(path, "r", encoding="utf-8") as f:
        for line in f:
            line = line.rstrip("\n")
            if pattern.match(line):
                print(line)

Complexity

Measure	Complexity
Time	O(n)
Space	O(1) to O(n) auxiliary

Frequently asked questions

How hard is LeetCode 193. Valid Phone Numbers?: LeetCode 193. Valid Phone Numbers is rated Easy on LeetCode.
What topics does LeetCode 193. Valid Phone Numbers cover?: LeetCode 193. Valid Phone Numbers is tagged Shell on LeetCode.