石头剪刀布游戏 - 华为OD统一考试(C卷)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

func main() {
	hash := map[string][]string{}
	in := bufio.NewScanner(os.Stdin)
	winner := map[rune]string{
		'A': "B",
		'B': "C",
		'C': "A",
	}

	for in.Scan() {
		str := in.Text()
		if len(str) == 0 {
			break
		}
		s := strings.Split(str, " ")

		hash[s[1]] = append(hash[s[1]], s[0])
	}

	if len(hash) != 2 {
		fmt.Println("NULL")
		return
	}

	for ch := 'A'; ch <= 'C'; ch++ {
		if _, ok := hash[string(ch)]; !ok {
			win := winner[ch]
			for _, name := range hash[win] {
				fmt.Println(name)
			}
			return
		}
	}

}