Submission #1677958

---

Source Code Expand

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func main() {
	ns := newfastScanner()
	N := ns.NextInt()
	K := ns.NextInt()
	A := make([]int, K)
	target := make([]bool, N)
	for i := 0; i < K; i++ {
		A[i] = ns.NextInt() - 1
		target[A[i]] = true
	}
	S := make([]string, N)
	for i := 0; i < N; i++ {
		S[i] = ns.Next()
	}
	if K == N {
		fmt.Println("")
		return
	}
	ma := 0
	mi := len(S[A[0]]) // ひとつ検索したいサイトを選んでその長さ
	for i := 0; i < N; i++ {
		if i == A[0] {
			continue
		}
		l := min(len(S[A[0]]), len(S[i]))
		for j := 0; j < min(len(S[A[0]]), len(S[i])); j++ {
			if S[A[0]][j] != S[i][j] {
				l = j
				break
			}
		}
		if target[i] {
			mi = min(mi, l)
		} else {
			ma = max(ma, l)
		}
	}
	if ma < mi {
		fmt.Println(S[A[0]][0 : ma+1])
	} else {
		fmt.Println("-1")
	}
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

type fastScanner struct {
	r   *bufio.Reader
	buf []byte
	p   int
}

func newfastScanner() *fastScanner {
	rdr := bufio.NewReaderSize(os.Stdin, 1024)
	return &fastScanner{r: rdr}
}
func (s *fastScanner) Next() string {
	s.pre()
	start := s.p
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			break
		}
	}
	result := string(s.buf[start:s.p])
	s.p++
	return result
}
func (s *fastScanner) NextLine() string {
	s.pre()
	start := s.p
	s.p = len(s.buf)
	return string(s.buf[start:])
}
func (s *fastScanner) NextInt() int {
	v, _ := strconv.Atoi(s.Next())
	return v
}
func (s *fastScanner) pre() {
	if s.p >= len(s.buf) {
		s.readLine()
		s.p = 0
	}
}
func (s *fastScanner) readLine() {
	s.buf = make([]byte, 0)
	for {
		l, p, e := s.r.ReadLine()
		if e != nil {
			panic(e)
		}
		s.buf = append(s.buf, l...)
		if !p {
			break
		}
	}
}

Submission Info

Judge Result