LeetCode 318. Maximum Product of Word Lengths

class Solution {
public:
    vector<int> nums;
    int maxProduct(vector<string>& words) {
        
        nums = vector<int>(words.size());
        for(int i=0;i<words.size();i++)
        {
            nums[i]=compute(words[i]);
        }
        
        int ans=0;
        for(int i=0;i<words.size();i++)
        {
            for(int j=i+1;j<words.size();j++)
            {
                if(!(nums[i]&nums[j]))
                {
                    if(ans < words[i].length()*words[j].length())
                        ans = words[i].length()*words[j].length();
                }
            }
        }
        return ans;
    }
    
    int compute(string s)
    {
        int bit = 0;
        for(int i=0;i<s.length();i++)
            bit |= (1<<(s[i]-'a'));
      
        return bit;
    }
};