結果

問題 No.416 旅行会社
コンテスト
ユーザー tenten
提出日時 2022-08-23 08:38:32
言語 Java
(openjdk 23)
結果
AC  
実行時間 1,604 ms / 4,000 ms
コード長 4,184 bytes
コンパイル時間 3,145 ms
コンパイル使用メモリ 80,276 KB
実行使用メモリ 94,848 KB
最終ジャッジ日時 2024-12-14 21:16:58
合計ジャッジ時間 20,273 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge2
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ファイルパターン 結果
other AC * 21
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ソースコード

diff # 

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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        int q = sc.nextInt();
        HashSet<Bridge> bridges = new HashSet<>();
        for (int i = 0; i < m; i++) {
            bridges.add(new Bridge(sc.nextInt() - 1, sc.nextInt() - 1));
        }
        Bridge[] brokens = new Bridge[q];
        for (int i = 0; i < q; i++) {
            brokens[i] = new Bridge(sc.nextInt() - 1, sc.nextInt() - 1);
            bridges.remove(brokens[i]);
        }
        UnionFindTree uft = new UnionFindTree(n);
        for (Bridge x : bridges) {
            uft.unite(x);
        }
        int[] ans = new int[n];
        for (int x : uft.getSet(0)) {
            ans[x] = -1;
        }
        for (int i = q - 1; i >= 0; i--) {
            HashSet<Integer> tmp = null;
            if (uft.same(0, brokens[i].left) && !uft.same(0, brokens[i].right)) {
                tmp = uft.getSet(brokens[i].right);
            } else if (uft.same(0, brokens[i].right) && !uft.same(0, brokens[i].left)) {
                tmp = uft.getSet(brokens[i].left);
            } else {
                uft.unite(brokens[i]);
                continue;
            }
            for (int x : tmp) {
                ans[x] = i + 1;
            }
            uft.unite(brokens[i]);
        }
        StringBuilder sb = new StringBuilder();
        for (int i = 1; i < n; i++) {
            sb.append(ans[i]).append("\n");
        }
        System.out.print(sb);
    }
    
    static class UnionFindTree {
        int[] parents;
        ArrayList<HashSet<Integer>> group = new ArrayList<>();
        
        public UnionFindTree(int size) {
            parents = new int[size];
            for (int i = 0; i < size; i++) {
                parents[i] = i;
                group.add(new HashSet<>());
                group.get(i).add(i);
            }
        }
        
        public int find(int x) {
            if (x == parents[x]) {
                return x;
            } else {
                return parents[x] = find(parents[x]);
            }
        }
        
        public boolean same(int x, int y) {
            return find(x) == find(y);
        }
        
        public boolean same(Bridge b) {
            return same(b.left, b.right);
        }
        
        public void unite(Bridge b) {
            unite(b.left, b.right);
        }
        
        public void unite(int x, int y) {
            int xx = find(x);
            int yy = find(y);
            if (xx == yy) {
                return;
            }
            if (group.get(xx).size() < group.get(yy).size()) {
                parents[xx] = yy;
                group.get(yy).addAll(group.get(xx));
            } else {
                parents[yy] = xx;
                group.get(xx).addAll(group.get(yy));
            }
        }
        
        public HashSet<Integer> getSet(int x) {
            return group.get(find(x));
        }
    }
    
    static class Bridge {
        int left;
        int right;
        
        public Bridge(int left, int right) {
            this.left = left;
            this.right = right;
        }
        
        public int hashCode() {
            return left;
        }
        
        public boolean equals(Object o) {
            Bridge b = (Bridge)o;
            return b.left == left && b.right == right;
        }
    }
}

class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    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 String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}
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