E.java

package atcoder.other2016.codefestival2016.qualb;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;

public class E {
    public static void main(String[] args) {
        InputReader in = new InputReader(System.in);
        PrintWriter out = new PrintWriter(System.out);

        int n = in.nextInt();
        char[][] s = new char[n][];
        for (int i = 0; i < n ; i++) {
            s[i] = in.nextToken().toCharArray();
        }

        PrefixAutomaton trie = new PrefixAutomaton(s);
      
        // 不要な辺を圧縮する
        trie.compress();
    
        // cnt[head] := head以下にある文字列の数を準備
        trie.goup();

        int[] ord = new int[26];
        int q = in.nextInt();
        while (--q >= 0) {
            int k = in.nextInt()-1;
            char[] target = s[k];
            char[] oc = in.nextToken().toCharArray();
            for (int i = 0; i < 26 ; i++) {
                ord[oc[i]-'a'] = i;
            }

            int head = 0;
            int cnt = 0;
            while (true) {
                // cmp[head] := ノード番号 head において何番目の文字を比較するか
                int cmp = trie.cmp[head];
              
                // この地点で終わってる文字を答えに足す
                cnt += trie.hereCnt[head];
                if (cmp >= target.length) {
                    break;
                }

                // 本実装では26回分ループを回しているが、各trie上の各頂点で存在する辺の配列を持っておけば高速化が見込める。
                int myindex = ord[target[cmp]-'a'];
                for (int i = 0 ; i < 26 ; i++) {
                    int nextID = trie.next[head][i];
                    if (nextID == 0) {
                        continue;
                    }
                    // 自分のインデックスより若い文字列を足す
                    if (ord[i] < myindex) {
                        cnt += trie.cnt[nextID];
                    }
                }
                head = trie.next[head][target[cmp]-'a'];
            }
            out.println(cnt);
        }
        out.flush();
    }

    // trie
    static class PrefixAutomaton {
        int n;
        char[][] words;
        int[][] next;
        int[][] allNext;
        int[] parentId;
        int[] lastCharacter;
        int[] cnt;
        int[] hereCnt;
        int[] cmp;
        int ni;

        public PrefixAutomaton(char[][] words) {
            n = 1;
            this.words = words;
            for (int i = 0; i < words.length ; i++) {
                n += words[i].length;
            }
            next = new int[n+1][26];
            allNext = new int[n+1][26];
            parentId = new int[n+1];
            lastCharacter = new int[n+1];
            cnt = new int[n+1];
            hereCnt = new int[n+1];
            cmp = new int[n+1];
            ni = 1;
            for (char[] w : words) {
                add(w);
            }
        }

        private int go(char[] l) {
            int head = 0;
            for (int i = 0; i < l.length ; i++) {
                int idx = cmp[head];
                if (idx >= l.length) {
                    break;
                }
                head = next[head][l[idx]-'a'];
            }
            return head;
        }

        private void add(char[] c) {
            int head = 0;
            for (int i = 0; i < c.length ; i++) {
                int ci = c[i]-'a';
                if (next[head][ci] == 0) {
                    next[head][ci] = ni++;
                }
                parentId[next[head][ci]] = head;
                cmp[head] = i;
                head = next[head][ci];
                lastCharacter[head] = ci;
            }
            cmp[head] = c.length;
            cnt[head]++;
            hereCnt[head]++;
        }

        public void compress() {
            for (int i = 1 ; i < ni ; i++) {
                int has = 0;
                int onlyID = -1;
                for (int k = 0 ; k < 26 ; k++) {
                    if (next[i][k] != 0) {
                        onlyID = next[i][k];
                        has++;
                    }
                }
              
                // 辺が一つしか無い かつ 終端の頂点でもない => 無くても問題ない
                if (has == 1 && hereCnt[i] == 0) {
                    int my = lastCharacter[i];
                    next[parentId[i]][my] = onlyID;
                    parentId[onlyID] = parentId[i];
                    lastCharacter[onlyID] = my;
                }
            }
        }

        public void goup() {
            for (int i = ni-1 ; i >= 1 ; i--) {
                cnt[parentId[i]] += cnt[i];
            }
        }
    }
  
    // 以下テンプレにつき略
}

E2.java

package atcoder.other2016.codefestival2016.qualb;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;

/**
 * Another solution.
 */
public class E2 {
    public static void main(String[] args) {
        InputReader in = new InputReader(System.in);
        PrintWriter out = new PrintWriter(System.out);

        int n = in.nextInt();
        char[][] s = new char[n][];
        for (int i = 0; i < n ; i++) {
            s[i] = in.nextToken().toCharArray();
        }

        PrefixAutomaton trie = new PrefixAutomaton(s);
        trie.goup();

        int q = in.nextInt();
        List<Query> queries = new ArrayList<>();
        for (int i = 0; i < q ; i++) {
            int k = in.nextInt()-1;
            char[] oc = in.nextToken().toCharArray();
            int[] ord = new int[26];
            for (int oi = 0; oi < 26 ; oi++) {
                ord[oc[oi]-'a'] = oi;
            }
            queries.add(new Query(i, k, ord));
        }
        Collections.sort(queries, (a, b) -> a.sidx - b.sidx);

        int[] ans = new int[q];
        for (int f = 0; f < q ; ) {
            int t = f;
            while (t < q && queries.get(f).sidx == queries.get(t).sidx) {
                t++;
            }
            char[] target = s[queries.get(f).sidx];
            int[][] table = trie.getTable(target);

            for (int qi = f ; qi < t ; qi++) {
                int qid = queries.get(qi).qidx;
                int[] ord = queries.get(qi).ord;
                int qa = 0;
                for (int i = 0 ; i < 26 ; i++) {
                    for (int j = i+1 ; j < 26 ; j++) {
                        if (ord[i] < ord[j]) {
                            // iがjより若いので答えに table[i][j] を足す
                            qa += table[i][j];
                        } else {
                            // jがiより若いので答えに table[j][i] を足す
                            qa += table[j][i];
                        }
                    }
                }
                // table[0][0] := 自分をprefixに持つ文字列の数
                ans[qid] = qa + table[0][0];
            }
            f = t;
        }

        for (int i = 0; i < q ; i++) {
            out.println(ans[i]+1);
        }
        out.flush();
    }

    static class Query {
        int qidx;
        int sidx;
        int[] ord;

        public Query(int q, int s, int[] o) {
            qidx = q;
            sidx = s;
            ord = o;
        }
    }

    static class PrefixAutomaton {
        int n;
        char[][] words;
        int[][] next;
        int[][] allNext;
        int[] parentId;
        int[] lastCharacter;
        int[] cnt;
        int[] hereCnt;
        int[] cmp;
        int ni;

        public PrefixAutomaton(char[][] words) {
            n = 1;
            this.words = words;
            for (int i = 0; i < words.length ; i++) {
                n += words[i].length;
            }
            next = new int[n+1][26];
            allNext = new int[n+1][26];
            parentId = new int[n+1];
            lastCharacter = new int[n+1];
            cnt = new int[n+1];
            hereCnt = new int[n+1];
            cmp = new int[n+1];
            ni = 1;
            for (char[] w : words) {
                add(w);
            }
        }

        // 比較用テーブルを作る
        public int[][] getTable(char[] l) {
            // table[x][y] := x が y より若い時、答えに table[x][y] を足し込む
            int[][] table = new int[26][26];
            int head = 0;
            for (int i = 0; i < l.length ; i++) {
                // 変な実装方法だけど、自身のprefixとなる文字列の数を table[0][0] に足し込んでいる。
                // 比較では table[0][0] は使わないので一応これで動く。
                table[0][0] += hereCnt[head];
                int idx = cmp[head];
                if (idx >= l.length) {
                    break;
                }

                int myIdx = l[idx]-'a';
                for (int e = 0 ; e < 26 ; e++) {
                    if (next[head][e] != 0 && e != myIdx) {
                        table[e][myIdx] += cnt[next[head][e]];
                    }
                }
                head = next[head][myIdx];
            }
            return table;
        }

        private int go(char[] l) {
            int head = 0;
            for (int i = 0; i < l.length ; i++) {
                int idx = cmp[head];
                if (idx >= l.length) {
                    break;
                }
                head = next[head][l[idx]-'a'];
            }
            return head;
        }

        private void add(char[] c) {
            int head = 0;
            for (int i = 0; i < c.length ; i++) {
                int ci = c[i]-'a';
                if (next[head][ci] == 0) {
                    next[head][ci] = ni++;
                }
                parentId[next[head][ci]] = head;
                cmp[head] = i;
                head = next[head][ci];
                lastCharacter[head] = ci;
            }
            cmp[head] = c.length;
            cnt[head]++;
            hereCnt[head]++;
        }

        public void goup() {
            for (int i = ni-1 ; i >= 1 ; i--) {
                cnt[parentId[i]] += cnt[i];
            }
        }
    }
  
    // 以下テンプレにつき略
}