for i := 0; i < last; i++ {
		lenSuffix := longestCommonSuffix(pattern, pattern[1:i+1])
		if pattern[i-lenSuffix] != pattern[last-lenSuffix] {
			// (last-i) is the shift, and lenSuffix is len(suffix).
			f.goodSuffixSkip[last-lenSuffix] = lenSuffix + last - i
		}
	}

	return f
}

func longestCommonSuffix(a, b string) (i int) {
	for ; i < len(a) && i < len(b); i++ {