class Solution {
    public List<Integer> findAnagrams(String s, String p) {
        List<Integer> res = new ArrayList();

        if(s.length()==0 ||s==null) return res;
        int[] char_counts = new int[26];
        for(char c : p.toCharArray()){
            char_counts[c-'a']++;
        }

        int left=0;
        int right=0;
        int count = p.length();

        while(right<s.length()){
            if(char_counts[s.charAt(right++) - 'a']-- >=1 ) count--;
            
            if(count==0) res.add(left);

            if(right-left==p.length() && char_counts[s.charAt(left++) - 'a']++ >=0 ) count++;
        }
        return res;
    }
}