Submission #4036392

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Source Code Expand

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

public class Main {

    static int N, M;
    static Edge[] E;
    static int Q;
    static int[] S, T;

    public static void main(String[] args) {
        FastScanner sc = new FastScanner(System.in);
        N = sc.nextInt();
        M = sc.nextInt();
        E = new Edge[M];
        for (int i = 0; i < M; i++) {
            E[i] = new Edge(sc.nextInt()-1, sc.nextInt()-1, sc.nextInt());
        }
        Q = sc.nextInt();
        S = new int[Q];
        T = new int[Q];
        for (int i = 0; i < Q; i++) {
            S[i] = sc.nextInt()-1;
            T[i] = sc.nextInt()-1;
        }

        writeLines(solve());
    }

    static long[] solve() {
        kruskal(N, E);
        int[][] maxEdges = buildMaxEdge();

        long[] ans = new long[Q];
        for (int i = 0; i < Q; i++) {
            ans[i] = mstCost - maxEdges[S[i]][T[i]];
        }
        return ans;
    }

    static int[][] buildMaxEdge() {
        int[][] maxEdges = new int[N][N];
        boolean[][] used = new boolean[N][N];
        ArrayDeque<Integer> q = new ArrayDeque<>();
        for (int i = 0; i < N; i++) {
            q.add(i);
            used[i][i] = true;
            maxEdges[i][i] = -1;

            while(!q.isEmpty()) {
                int a = q.poll();
                for (Edge e : mst[a]) {
                    int b = e.opposite(a);
                    if( !used[i][b] ) {
                        int m = Math.max(maxEdges[i][a], e.c);
                        q.add( b );
                        maxEdges[i][b] = m;
                        used[i][b] = true;
                    }
                }
            }
        }
        return maxEdges;
    }

    static List<Edge>[] mst;
    static long mstCost;

    static void kruskal(int N, Edge[] E) {
        Arrays.sort(E, Comparator.comparingInt(e -> e.c));
        List<Edge>[] T = new List[N];
        for (int i = 0; i < N; i++) {
            T[i] = new ArrayList<>();
        }

        long cost = 0;
        UnionFind uf = new UnionFind(N);
        for (Edge e : E) {
            if( uf.isSame(e.a, e.b) ) continue;

            T[e.a].add(e);
            T[e.b].add(e);
            uf.unite(e.a, e.b);
            cost += e.c;
        }

        mst = T;
        mstCost = cost;
    }

    static class Edge {
        final int a, b, c;

        public Edge(int a, int b, int c) {
            this.a = a;
            this.b = b;
            this.c = c;
        }

        int opposite(int x) {
            return a == x ? b : a;
        }
    }

    static class UnionFind {

        private final int[] parent;
        private final int[] rank;

        public UnionFind(int n) {
            parent = new int[n];
            rank = new int[n];
            for (int i = 0; i < n; i++) {
                parent[i] = i;
                rank[i] = 0;
            }
        }

        public int root(int i) {
            if( parent[i] == i ) {
                return i;
            } else {
                return parent[i] = root(parent[i]);
            }
        }

        public void unite(int i, int j) {
            int ri = root(i);
            int rj = root(j);
            if( ri == rj ) return;

            if( rank[ri] < rank[rj] ) {
                parent[ri] = rj;

            } else {
                parent[rj] = ri;
                if( rank[ri] == rank[rj] ) {
                    rank[ri]++;
                }
            }
        }

        public boolean isSame(int a, int b) {
            return root(a) == root(b);
        }
    }

    @SuppressWarnings("unused")
    static class FastScanner {
        private BufferedReader reader;
        private StringTokenizer tokenizer;

        FastScanner(InputStream in) {
            reader = new BufferedReader(new InputStreamReader(in));
            tokenizer = null;
        }

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

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

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

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

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

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

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

    static void writeLines(int[] as) {
        PrintWriter pw = new PrintWriter(System.out);
        for (int a : as) pw.println(a);
        pw.flush();
    }

    static void writeLines(long[] as) {
        PrintWriter pw = new PrintWriter(System.out);
        for (long a : as) pw.println(a);
        pw.flush();
    }

    static void writeSingleLine(int[] as) {
        PrintWriter pw = new PrintWriter(System.out);
        for (int i = 0; i < as.length; i++) {
            if (i != 0) pw.print(" ");
            pw.print(as[i]);
        }
        pw.println();
        pw.flush();
    }

    static int max(int... as) {
        int max = Integer.MIN_VALUE;
        for (int a : as) max = Math.max(a, max);
        return max;
    }

    static int min(int... as) {
        int min = Integer.MAX_VALUE;
        for (int a : as) min = Math.min(a, min);
        return min;
    }

    static void debug(Object... args) {
        StringJoiner j = new StringJoiner(" ");
        for (Object arg : args) {
            if (arg == null) j.add("null");
            else if (arg instanceof int[]) j.add(Arrays.toString((int[]) arg));
            else if (arg instanceof long[]) j.add(Arrays.toString((long[]) arg));
            else if (arg instanceof double[]) j.add(Arrays.toString((double[]) arg));
            else if (arg instanceof Object[]) j.add(Arrays.toString((Object[]) arg));
            else j.add(arg.toString());
        }
        System.err.println(j.toString());
    }

    static void printSingleLine(int[] array) {
        PrintWriter pw = new PrintWriter(System.out);
        for (int i = 0; i < array.length; i++) {
            if (i != 0) pw.print(" ");
            pw.print(array[i]);
        }
        pw.println();
        pw.flush();
    }

    static int lowerBound(int[] array, int value) {
        int lo = 0, hi = array.length, mid;
        while (lo < hi) {
            mid = (hi + lo) / 2;
            if (array[mid] < value) lo = mid + 1;
            else hi = mid;
        }
        return lo;
    }

    static int upperBound(int[] array, int value) {
        int lo = 0, hi = array.length, mid;
        while (lo < hi) {
            mid = (hi + lo) / 2;
            if (array[mid] <= value) lo = mid + 1;
            else hi = mid;
        }
        return lo;
    }
}

Submission Info

Compile Error

Note: ./Main.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

Judge Result