[Python] | single loop unique O(N) solution
\n\t\t\n\t\tC=Counter()\n        ans=0\n        countrev=0\n        for word in words:\n            rev_word=word[::-1]\n           \n            if rev_word in
\n\t\t\n\t\tC=Counter()\n        ans=0\n        countrev=0\n        for word in words:\n            rev_word=word[::-1]\n           \n            if rev_word in C and C[rev_word]>0:\n                    \n                if rev_word==word:\n                    countrev-=1\n                ans+=4\n                C[rev_word]-=1    \n            else:\n                if rev_word==word:\n                    countrev+=1\n                C[word]+=1\n        \n        return ans+2 if countrev>0 else ans
['Python']