leetcode-go/leetcode/easy/551.student-attendance-record-i.go

func checkRecord(s string) bool {
	a, l := 0, 0
	for _, r := range s {
		switch r {
		case 'L':
			l++
		case 'A':
			a++
			fallthrough
		default:
			l = 0
		}
		if l == 3 || a == 2 {
			return false
		}
	}
	return true
}