Question

How to find the maximum length of a subarray having a sum equal to K in PHP

Answer 1

function maxSubArrayLenEqualsToK($arr, $k) {
    $current = 0;
    $len = 0;
    $hmap = array();
    $size = count($arr);
    
    for ($i = 0; $i < $size; $i++) {
        $current += $arr[$i];
        if ($current == $k) {
            $len = $i + 1;
        }
        else if (array_key_exists($current - $k, $hmap)) {
            $len = max($len, $i - $hmap[$current - $k]);
        }
        if (!array_key_exists($current,$hmap)) {
            $hmap[$current] = $i;
        }
    }
    
    return $len;
}

$arr = array(1, -1, 5, -2, -3, 2, 3, 3);

$K = 3;

// 1, -1, 5, -2 = 3 (4)
// 5, -2 = 3 (2)
// -2, -3, 2, 3, 3 = 3 (5)

echo maxSubArrayLenEqualsToK($arr, $K);



/*
run:

5

*/

 

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