Given an array and split it from a specified position, and move the first part of array add to the end.
Examples:
Input : arr[] = {12, 10, 5, 6, 52, 36} k = 2 Output : arr[] = {5, 6, 52, 36, 12, 10} Explanation : Split from index 2 and first part {12, 10} add to the end . Input : arr[] = {3, 1, 2} k = 1 Output : arr[] = {1, 2, 3} Explanation : Split from index 1 and first part add to the end.
A O(n*k) solution is discussed here.
This problem can be solved in O(n) time using the reversal algorithm discussed below,
1. Reverse array from 0 to n – 1 (where n is size of the array).
2. Reverse array from 0 to n – k – 1.
3. Reverse array from n – k to n – 1.
PHP
<?php // PHP program to Split the array and // add the first part to the end /* Function to reverse arr[] from index start to end*/ function rvereseArray(& $arr , $start , $end )
{ while ( $start < $end )
{
$temp = $arr [ $start ];
$arr [ $start ] = $arr [ $end ];
$arr [ $end ] = $temp ;
$start ++;
$end --;
}
} // Function to print an array function printArray(& $arr , $size )
{ for ( $i = 0; $i < $size ; $i ++)
echo $arr [ $i ] . " " ;
} /* Function to left rotate arr[] of size n by k */ function splitArr(& $arr , $k , $n )
{ rvereseArray( $arr , 0, $n - 1);
rvereseArray( $arr , 0, $n - $k - 1);
rvereseArray( $arr , $n - $k , $n - 1);
} /* Driver program to test above functions */ $arr = array ( 12, 10, 5, 6, 52, 36 );
$n = sizeof( $arr );
$k = 2;
// Function calling splitArr( $arr , $k , $n );
printArray( $arr , $n );
// This code is contributed // by Akanksha Rai(Abby_akku) ?> |
Output:
5 6 52 36 12 10
Please refer complete article on Split the array and add the first part to the end | Set 2 for more details!