1class Solution {2    public List<Integer> findAnagrams(String s, String p) {3        int[] need = new int[26], have = new int[26];4        for (char c : p.toCharArray()) need[c - 'a']++;5        List<Integer> ans = new ArrayList<>();6        for (int right = 0; right < s.length(); right++) {7            have[s.charAt(right) - 'a']++;8            if (right >= p.length()) have[s.charAt(right - p.length()) - 'a']--;9            if (right + 1 >= p.length() && Arrays.equals(need, have)) {10                ans.add(right + 1 - p.length());11            }12        }13        return ans;14    }15}