Given a matrix of n*n size, the task is to find whether all rows are circular rotations of each other or not.
Examples:
Input: mat[][] = 1, 2, 3
3, 1, 2
2, 3, 1
Output: Yes ,All rows are rotated permutation of each other.
Input: mat[3][3] = 1, 2, 33, 2, 1
1, 3, 2
Output: No, Explanation : As 3, 2, 1 is not a rotated or circular permutation of 1, 2, 3
The idea is based on the below article.
A Program to check if strings are rotations of each other or not
Steps :
- Create a string of first row elements and concatenate the string with itself so that string search operations can be efficiently performed. Let this string be str_cat.
- Traverse all remaining rows. For every row being traversed, create a string str_curr of current row elements. If str_curr is not a substring of str_cat, return false.
- Return true.
Below is the implementation of the above steps.
PHP
<?php // PHP program to check if all rows of a // matrix are rotations of each other$MAX = 1000;// Returns true if all rows of mat[0..n-1][0..n-1]// are rotations of each other.function isPermutedMatrix( &$mat, $n){ // Creating a string that contains // elements of first row. $str_cat = ""; for ($i = 0 ; $i < $n ; $i++) $str_cat = $str_cat . "-" . strval($mat[0][$i]); // Concatenating the string with itself // so that substring search operations // can be performed on this $str_cat = $str_cat . $str_cat; // Start traversing remaining rows for ($i = 1; $i < $n; $i++) { // Store the matrix into vector // in the form of strings $curr_str = ""; for ($j = 0 ; $j < $n ; $j++) $curr_str = $curr_str . "-" . strval($mat[$i][$j]); // Check if the current string is present // in the concatenated string or not if (strpos($str_cat, $curr_str)) return true; } return false;}// Driver Code$n = 4;$mat = array(array(1, 2, 3, 4), array(4, 1, 2, 3), array(3, 4, 1, 2), array(2, 3, 4, 1));if (isPermutedMatrix($mat, $n)) echo "Yes";else echo "No";// This code is contributed by ita_c?> |
Yes
Time complexity : O(n3)
Auxiliary Space : O(n)
Please refer complete article on Check if all rows of a matrix are circular rotations of each other for more details!
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 neveropen!
