結果

問題 No.2100 [Cherry Alpha C] Two-way Steps
コンテスト
ユーザー tenten
提出日時 2023-03-02 17:24:01
言語 Java
(openjdk 23)
結果
TLE  
実行時間 -
コード長 4,894 bytes
コンパイル時間 3,055 ms
コンパイル使用メモリ 98,124 KB
実行使用メモリ 64,840 KB
最終ジャッジ日時 2024-09-17 11:43:02
合計ジャッジ時間 12,485 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge5
このコードへのチャレンジ
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ファイルパターン 結果
other AC * 10 TLE * 1 -- * 37
権限があれば一括ダウンロードができます

ソースコード

diff # 

import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        int[] heights = new int[n];
        ArrayList<ArrayList<Integer>> graph = new ArrayList<>();
        ArrayList<ArrayList<Integer>> reverse = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            heights[i] = sc.nextInt();
            graph.add(new ArrayList<>());
            reverse.add(new ArrayList<>());
        }
        for (int i = 0; i < m; i++) {
            int a = sc.nextInt() - 1;
            int b = sc.nextInt() - 1;
            graph.get(a).add(b);
            reverse.get(b).add(a);
        }
        PriorityQueue<Path> queue = new PriorityQueue<>();
        queue.add(new Path(0, 0, 0));
        long[][] lefts = new long[2][n];
        Arrays.fill(lefts[0], Long.MIN_VALUE);
        Arrays.fill(lefts[1], Long.MIN_VALUE);
        while (queue.size() > 0) {
            Path p = queue.poll();
            if (lefts[p.type][p.idx] >= p.value) {
                continue;
            }
            lefts[p.type][p.idx] = p.value;
            for (int x : graph.get(p.idx)) {
                int nType;
                long nValue;
                if (heights[p.idx] < heights[x]) {
                    if (p.type == 1) {
                        continue;
                    }
                    nType = 1;
                    nValue = p.value + heights[x] - heights[p.idx];
                } else {
                    nType = 0;
                    nValue = p.value;
                }
                queue.add(new Path(x, nType, nValue));
            }
        }
        if (lefts[0][n - 1] == Long.MIN_VALUE && lefts[1][n - 1] == Long.MIN_VALUE) {
            System.out.println(-1);
        } else {
            System.out.println(Math.max(lefts[0][n - 1], lefts[1][n - 1]));
        }
        queue.add(new Path(n - 1, 0, 0));
        long[][] rights = new long[2][n];
        Arrays.fill(rights[0], Long.MIN_VALUE);
        Arrays.fill(rights[1], Long.MIN_VALUE);
        while (queue.size() > 0) {
            Path p = queue.poll();
            if (rights[p.type][p.idx] >= p.value) {
                continue;
            }
            rights[p.type][p.idx] = p.value;
            for (int x : reverse.get(p.idx)) {
                int nType;
                long nValue;
                if (heights[p.idx] < heights[x]) {
                    if (p.type == 1) {
                        continue;
                    }
                    nType = 1;
                    nValue = p.value + heights[x] - heights[p.idx];
                } else {
                    nType = 0;
                    nValue = p.value;
                }
                queue.add(new Path(x, nType, nValue));
            }
        }
        if (rights[0][0] == Long.MIN_VALUE && rights[1][0] == Long.MIN_VALUE) {
            System.out.println(-1);
        } else {
            System.out.println(Math.max(rights[0][0], rights[1][0]));
        }
    }
    
    static class  Path implements Comparable<Path> {
        int idx;
        int type;
        long value;
        
        public Path(int idx, int type, long value) {
            this.idx = idx;
            this.type = type;
            this.value = value;
        }
        
        public int compareTo(Path another) {
            if (value == another.value) {
                return 0;
            } else if (value < another.value) {
                return 1;
            } else {
                return -1;
            }
        }
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}
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