class Solution {
public:
    bool checkCnt(vector<int>& cnts, vector<int>& cntp){
        for(int i = 0; i < 26; i++){
            if(cnts[i] != cntp[i]) return false;
        }
        return true;
    }
    vector<int> findAnagrams(string s, string p) {
        vector<int> cntp(26);
        for(char c:p){ cntp[c-'a']++; }
        
        vector<int> ret;
        vector<int> cnts(26);
        for(int i = 0; i < min(p.length(), s.length()); i++){ 
            cnts[s[i] - 'a']++; 
        }

        if(checkCnt(cnts, cntp)) { ret.push_back(0);}

        for(int r = p.length(); r < s.length(); r++){ // sliding window
            int l = r - p.length() + 1;
            cnts[s[l-1] - 'a']--;
            cnts[s[r] - 'a']++;
            if(checkCnt(cnts, cntp)) { ret.push_back(l); }
        }
        return ret;
    }
};