Php Program to Check whether all the rotations of a given number is greater than or equal to the given number or not

Given an integer x, the task is to find if every k-cycle shift on the element produces a number greater than or equal to the same element. 
A k-cyclic shift of an integer x is a function that removes the last k digits of x and inserts them in its beginning. 
For example, the k-cyclic shifts of 123 are 312 for k=1 and 231 for k=2. Print Yes if the given condition is satisfied else print No.
Examples:

Input: x = 123 
Output : Yes 
The k-cyclic shifts of 123 are 312 for k=1 and 231 for k=2. 
Both 312 and 231 are greater than 123.
Input: 2214 
Output: No 
The k-cyclic shift of 2214 when k=2 is 1422 which is smaller than 2214 

Approach: Simply find all the possible k cyclic shifts of the number and check if all are greater than the given number or not.
Below is the implementation of the above approach: 

PHP

<?php
// PHP implementation of the approach

function CheckKCycles($n, $s)
{
    $ff = true;
    $x = 0;
    for ($i = 1; $i < $n; $i++)
    {

        // Splitting the number at index i
        // and adding to the front
        $x = strlen(substr($s, $i).substr($s, 0, $i));

        // Checking if the value is greater than
        // or equal to the given value
        if ($x >= strlen($s))
        {
            continue;
        }
        $ff = false;
        break;
    }
    if ($ff)
    {
        print("Yes");
    }
    else
    {
        print("No");
    }
}

// Driver code
$n = 3;
$s = "123";
CheckKCycles($n, $s);

// This code contributed by mits
?>

Output:

Yes

Time Complexity: O(N²), where N is the length of the given string. First it runs a loop for traversing the string and inside that substring function is used. So, the code will run in O(N²) time.

Auxiliary Space: O(1), no extra space required, so it is a constant.

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