leetcode-go/easy/500.keyboard-row.go

var rows map[rune]int = map[rune]int{
	'A': 1, 'S': 1, 'D': 1, 'F': 1, 'G': 1, 'H': 1, 'J': 1, 'K': 1, 'L': 1,
	'Z': 2, 'X': 2, 'C': 2, 'V': 2, 'B': 2, 'N': 2, 'M': 2,
}

func findWords(words []string) (res []string) {
	for i := range words {
		if isInOneRow(words[i]) {
			res = append(res, words[i])
		}
	}
	return
}

func isInOneRow(s string) bool {
	res := 0
	for _, r := range s {
		ch := toUpper(r)
		if val, ok := rows[ch]; ok {
			res |= val
		} else {
			res |= 4
		}
	}
	return res == 1 || res == 2 || res == 4
}

func toUpper(r rune) rune {
	if 'a' <= r {
		return rune(r - 32)
	}
	return r
}