PHP Program to Rotation Check with Explanation
PHP
Medium
PHP Strings
37 views
1 min read
85 words
This problem helps you practice core PHP fundamentals in a practical way. It builds intuition around rotation, check, yes. Let’s break it down step by step so you can implement it confidently.
Problem Statement
Check if b is a rotation of a (case-sensitive). Print YES or NO.
Input Format
Two lines a and b.
Output Format
YES or NO.
Constraints
|a|,|b|
Code Solution
This explanation is written for learning purposes and to help beginners understand the concept clearly.
<?php
$inputText=rtrim(stream_get_contents(STDIN));
if($inputText==='') exit;
$inputLines=preg_split('/\\R/', $inputText);
$a=$inputLines[0] ?? '';
$b=$inputLines[1] ?? '';
if(strlen($a)!==strlen($b)){ echo 'NO'; exit; }
$twice=$a.$a;
echo (strpos($twice,$b)!==false) ? 'YES' : 'NO';
?>
Common Mistakes
- Misreading input/output format.
- Not handling constraints and edge cases.
- Off-by-one errors in loops.
- Forgetting to reset variables between test cases (if any).
Solution Guide
Problem
Check if b is a rotation of a (case-sensitive). Print YES or NO.
Details
Common Mistakes
- Misreading input/output format.
- Not handling constraints and edge cases.
- Off-by-one errors in loops.
- Forgetting to reset variables between test cases (if any).
Official Solution
<?php
$inputText=rtrim(stream_get_contents(STDIN));
if($inputText==='') exit;
$inputLines=preg_split('/\\R/', $inputText);
$a=$inputLines[0] ?? '';
$b=$inputLines[1] ?? '';
if(strlen($a)!==strlen($b)){ echo 'NO'; exit; }
$twice=$a.$a;
echo (strpos($twice,$b)!==false) ? 'YES' : 'NO';
?>
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