Simple PHP solution
Complexity\n- Time complexity: O(n)\n Add your time complexity here, e.g. O(n) \n\n\n# Code\n\nclass Solution {\n\n    /**\n     * @param String[] $words\n     
# Complexity\n- Time complexity: $$O(n)$$\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n\n# Code\n```\nclass Solution {\n\n    /**\n     * @param String[] $words\n     * @return Integer\n     */\n    function maximumNumberOfStringPairs($words) {\n        //Here we\'ll keep words as array keys\n        $hash = [];\n        $counter = 0;\n        //for every item in $words\n        foreach ($words as $value) {\n            //if $hash has item with key == reverse $value then increment $counter\n            if ($hash[strrev($value)]) {\n                $counter++;\n            } else {\n                //if item has not pair then just save it in $hash\n                $hash[$value] = \'1\';\n            }\n        }\n        return $counter;\n    }\n}\n```\n# P.S.\nUpvote if it helps you)\n
['PHP']