leetcode-go/medium/423.reconstruct-original-digits-from-english.go

func originalDigits(s string) string {
	freq, cnt := make([]int, 256), make([]int, 10)
	for _, r := range s {
		freq[r]++
	}
	cnt[0] = wordCnt(freq, 'z', "o")
	cnt[2] = wordCnt(freq, 'w', "o")
	cnt[4] = wordCnt(freq, 'u', "fo")
	cnt[6] = wordCnt(freq, 'x', "s")
	cnt[8] = wordCnt(freq, 'g', "h")
	//
	cnt[1] = wordCnt(freq, 'o', "n")
	cnt[3] = freq['h']
	cnt[5] = freq['f']
	cnt[7] = wordCnt(freq, 's', "n")
	//
	cnt[9] = freq['n'] / 2
	var sb strings.Builder
	for i := 0; i < 10; i++ {
		for j := 0; j < cnt[i]; j++ {
			sb.WriteByte(byte(i + '0'))
		}
	}
	return sb.String()
}

func wordCnt(freq []int, key byte, word string) int {
	cnt := freq[key]
	for _, r := range word {
		freq[r] -= cnt
	}
	return cnt
}