diff --git a/problems/0454.四数相加II.md b/problems/0454.四数相加II.md index 4e61dc2f..9fe01ad1 100644 --- a/problems/0454.四数相加II.md +++ b/problems/0454.四数相加II.md @@ -220,7 +220,37 @@ var fourSumCount = function(nums1, nums2, nums3, nums4) { }; ``` - +PHP: +```php +class Solution { + /** + * @param Integer[] $nums1 + * @param Integer[] $nums2 + * @param Integer[] $nums3 + * @param Integer[] $nums4 + * @return Integer + */ + function fourSumCount($nums1, $nums2, $nums3, $nums4) { + $map = []; + foreach ($nums1 as $n1) { + foreach ($nums2 as $n2) { + $temp = $n1 + $n2; + $map[$temp] = isset($map[$temp]) ? $map[$temp]+1 : 1; + } + } + $count = 0; + foreach ($nums3 as $n3) { + foreach ($nums4 as $n4) { + $temp = 0 - $n3 - $n4; + if (isset($map[$temp])) { + $count += $map[$temp]; + } + } + } + return $count; + } +} +``` -----------------------