438. 找到字符串中所有字母异位词

class Solution {
public:
    vector<int> findAnagrams(string s, string p) {
        vector<int> SV(26, 0);
        vector<int> PV(26, 0);
        vector<int> ans;
        for(auto ch : p) PV[ch - 'a']++;
        for(int ii = 0; ii < s.size(); ii++) {
            SV[s[ii] - 'a']++;
            if(ii >= p.size() - 1) {
                int jj = 0;
                while(jj < 26 && SV[jj] >= PV[jj]) jj++;
                if(jj == 26) ans.push_back(ii - p.size() + 1);
                SV[s[ii - p.size() + 1] - 'a']--;
            }
        }
        return ans;
    }
};