Php Program for Size of The Subarray With Maximum Sum
Last Updated :
17 May, 2023
An array is given, find length of the subarray having maximum sum.
Examples :
Input : a[] = {1, -2, 1, 1, -2, 1}
Output : Length of the subarray is 2
Explanation: Subarray with consecutive elements
and maximum sum will be {1, 1}. So length is 2
Input : ar[] = { -2, -3, 4, -1, -2, 1, 5, -3 }
Output : Length of the subarray is 5
Explanation: Subarray with consecutive elements
and maximum sum will be {4, -1, -2, 1, 5}.
This problem is mainly a variation of Largest Sum Contiguous Subarray Problem.
The idea is to update starting index whenever sum ending here becomes less than 0.
PHP
<?php
function maxSubArraySum( $a , $size ) {
$max_so_far = PHP_INT_MIN;
$max_ending_here = 0;
$start = 0;
$end = 0;
$s = 0;
for ( $i = 0; $i < $size ; $i ++) {
$max_ending_here += $a [ $i ];
if ( $max_so_far < $max_ending_here ) {
$max_so_far = $max_ending_here ;
$start = $s ;
$end = $i ;
}
if ( $max_ending_here < 0) {
$max_ending_here = 0;
$s = $i + 1;
}
}
return ( $end - $start + 1);
}
$a = [-2, -3, 4, -1, -2, 1, 5, -3];
$n = count ( $a );
echo maxSubArraySum( $a , $n );
?>
|
Time Complexity: O(N) where N is size of the input array. This is because a for loop is executing from 1 to size of the array.
Space Complexity: O(1) as no extra space has been taken.
Please refer complete article on Size of The Subarray With Maximum Sum for more details!
Like Article
Suggest improvement
Share your thoughts in the comments
Please Login to comment...