func findAnagrams(s string, p string) (res []int) {
	freq, curr := make([]int, 256), make([]int, 256)
	for _, r := range p {
		freq[r]++
	}
	m, n := len(s), len(p)
	ss := []rune(s)
	for i := 0; i < m; i++ {
		curr[ss[i]]++
		if n-1 <= i {
			same := true
			for j := 'a'; j <= 'z'; j++ {
				if freq[j] != curr[j] {
					same = false
				}
			}
			if same {
				res = append(res, i-n+1)
			}
			curr[ss[i-n+1]]--
		}
	}
	return
}