結果

問題 No.1103 Directed Length Sum
ユーザー shojin_proshojin_pro
提出日時 2020-07-04 00:09:57
言語 Java21
(openjdk 21)
結果
AC  
実行時間 956 ms / 3,000 ms
コード長 3,091 bytes
コンパイル時間 2,393 ms
コンパイル使用メモリ 78,792 KB
実行使用メモリ 81,360 KB
最終ジャッジ日時 2024-09-17 05:13:30
合計ジャッジ時間 17,062 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge2
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 54 ms
50,136 KB
testcase_01 AC 53 ms
49,916 KB
testcase_02 AC 653 ms
81,360 KB
testcase_03 AC 631 ms
71,940 KB
testcase_04 AC 654 ms
59,372 KB
testcase_05 AC 796 ms
68,912 KB
testcase_06 AC 576 ms
53,176 KB
testcase_07 AC 269 ms
45,648 KB
testcase_08 AC 340 ms
49,856 KB
testcase_09 AC 228 ms
44,712 KB
testcase_10 AC 445 ms
54,984 KB
testcase_11 AC 670 ms
61,476 KB
testcase_12 AC 700 ms
62,932 KB
testcase_13 AC 419 ms
53,212 KB
testcase_14 AC 207 ms
45,012 KB
testcase_15 AC 613 ms
61,568 KB
testcase_16 AC 771 ms
66,228 KB
testcase_17 AC 765 ms
63,920 KB
testcase_18 AC 403 ms
50,508 KB
testcase_19 AC 956 ms
70,612 KB
testcase_20 AC 242 ms
46,276 KB
testcase_21 AC 313 ms
49,572 KB
testcase_22 AC 549 ms
64,428 KB
testcase_23 AC 659 ms
55,848 KB
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ソースコード

diff # 

import java.util.*;
import java.io.*;
 
public class Main {
    static boolean[] arrived;
    static long[] cum;
    public static void main(String[] args) throws Exception {
        long mod = (long)Math.pow(10,9)+7;
        FastScanner sc = new FastScanner(System.in);
        int n = sc.nextInt();
        int[] from = new int[n+1];
        cum = new long[n+1];
        for(int i = 1; i <= n; i++){
            cum[i] += cum[i-1]+i;
        }
        for(int i = 0; i < n-1; i++){
            int a = sc.nextInt();
            int b = sc.nextInt();
            from[b] = a;
        }
        long ans = 0;
        int[] step = new int[n+1];
        boolean[] arrived = new boolean[n+1];
        Deque<Integer> q = new ArrayDeque<>();
        for(int i = 1; i <= n; i++){
            int cnt = 0;
            if(arrived[i]){
                continue;
            }
            int now = i;
            while(from[now] != 0){
                if(arrived[now]){
                    cnt = step[now];
                    break;
                }else{
                    arrived[now] = true;
                    q.add(now);
                }
                now = from[now];
            }
            while(q.size() != 0){
                long tmp = cum[q.size()+cnt];
                ans += tmp;
                ans %= mod;
                int prev = q.pollFirst();
                step[prev] = q.size()+1+cnt;
            }
        }
        System.out.println(ans);
    }
}

class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;
    public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    }

    public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken("\n");
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public double nextDouble() {
         return Double.parseDouble(next());
    }
    
    public String[] nextArray(int n) {
        String[] a = new String[n];
        for (int i = 0; i < n; i++)
            a[i] = next();
        return a;
    }

    public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    } 
}
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