Leetcode-5176 Number of Valid Words for Each Puzzle(猜字谜)

#define _for(i,a,b) for(int i = (a);i < b;i ++)
#define _rep(i,a,b) for(int i = (a);i > b;i --)
class Solution
{
    public:
        vector<int> findNumOfValidWords(vector<string>& words, vector<string>& puzzles)
        {
            map<int,int> m;
            _for(i,0,words.size())
            {
                int st = 0;
                int cnt = 0;
                _for(j,0,words[i].size())
                    st |= 1<<words[i][j]-'a';
                m[st] ++;
            }
            vector<int> vV;

            _for(i,0,puzzles.size())
            {
                int sup = 0;
                int rnt = 0;
                _for(j,0,puzzles[i].size())
                    sup |= 1<<puzzles[i][j]-'a';
                int sub = sup;
                do
                {
                    if((sub & (1<<puzzles[i][0]-'a')))
                        rnt += m[sub];
                    sub = (sub-1) & sup;
                }
                while(sub != sup);   // 处理完之后 会有 -1&sup = sup
                vV.push_back(rnt);
            }
            return vV;
        }
};