Submission #1119536

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119536		johu	Job Scheduling (CEOI12_jobs)	Java	70 / 100	1073 ms	28752 KiB

jobs

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

public class jobs {
    public static void main(String[] args) throws IOException {
        FastInputReader reader = new FastInputReader(System.in);

        int n = reader.nextInt(); // Number of days
        int d = reader.nextInt(); // Delay allowed
        int m = reader.nextInt(); // Number of events

        if (m <= 300000) {
            // Handle small cases with ArrayList
            handleSmallCases(reader, n, d, m);
        } else {
            // Handle large cases
            handleLargeCases(reader, n, d, m);
        }
    }

    private static void handleSmallCases(FastInputReader reader, int n, int d, int m) throws IOException {
        List<Pair> a = new ArrayList<>(m + 2);
        for (int i = 1; i <= m; i++) {
            a.add(new Pair(reader.nextInt(), i));
        }
        a.add(new Pair(1000000000, 0)); // Dummy pair for boundary

        a.sort(Comparator.naturalOrder());

        int l = 0, r = m;

        while (r - l > 1) {
            int mid = (l + r) / 2;
            int p = 0;

            for (int i = 1; i <= n; i++) {
                if (a.get(p).fr + d < i) {
                    break;
                }
                int cnt = 0;
                while (cnt < mid && p < m && a.get(p).fr <= i) {
                    cnt++;
                    p++;
                }
            }

            if (p >= m) {
                r = mid;
            } else {
                l = mid;
            }
        }

        System.out.println(r);
        StringBuilder sb = new StringBuilder();
        int p = 0;

        for (int i = 1; i <= n; i++) {
            int cnt = 0;
            while (cnt < r && p < m && a.get(p).fr <= i) {
                sb.append(a.get(p).sc).append(" ");
                cnt++;
                p++;
            }
            sb.append("0\n");
        }

        System.out.print(sb);
    }

    private static void handleLargeCases(FastInputReader reader, int n, int d, int m) throws IOException {
        int[] fr = new int[m + 1];
        int[] sc = new int[m + 1];

        // Read input values into `fr` and assign indices to `sc`
        for (int i = 1; i <= m; i++) {
            fr[i] = reader.nextInt();
            sc[i] = i;
        }

        // Sort jobs by their earliest start time (`fr`)
        quickSort(fr, sc, 1, m);

        int l = 0, r = m;

        // Binary search for the smallest `r`
        while (r - l > 1) {
            int mid = (l + r) / 2;
            int p = 1; // Pointer to track job indices

            // Iterate over all days
            for (int i = 1; i <= n; i++) {
                // Skip jobs that can't start on the current day
                while (p <= m && fr[p] + d < i) p++;
                if (p > m) break; // Exit early if all jobs are assigned

                int cnt = 0;

                // Allocate jobs for the current day
                while (cnt < mid && p <= m && fr[p] <= i) {
                    cnt++;
                    p++;
                }
            }

            // Adjust binary search bounds
            if (p > m) {
                r = mid;
            } else {
                l = mid;
            }
        }

        // Output results
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        bw.write(r + "\n");

        int p = 1;
        for (int i = 1; i <= n; i++) {
            int cnt = 0;
            while (cnt < r && p <= m && fr[p] <= i) {
                bw.write(sc[p] + " ");
                cnt++;
                p++;
            }
            bw.write("0\n");
        }
        bw.flush();
    }

    private static void quickSort(int[] fr, int[] sc, int low, int high) {
        if (low < high) {
            int pivotIndex = partition(fr, sc, low, high);
            quickSort(fr, sc, low, pivotIndex - 1);
            quickSort(fr, sc, pivotIndex + 1, high);
        }
    }

    private static int partition(int[] fr, int[] sc, int low, int high) {
        int pivot = fr[high];
        int i = low - 1;
        for (int j = low; j < high; j++) {
            if (fr[j] <= pivot) {
                i++;
                swap(fr, sc, i, j);
            }
        }
        swap(fr, sc, i + 1, high);
        return i + 1;
    }

    private static void swap(int[] fr, int[] sc, int i, int j) {
        int tempFr = fr[i];
        fr[i] = fr[j];
        fr[j] = tempFr;

        int tempSc = sc[i];
        sc[i] = sc[j];
        sc[j] = tempSc;
    }

    static class Pair implements Comparable<Pair> {
        int fr, sc;

        Pair(int fr, int sc) {
            this.fr = fr;
            this.sc = sc;
        }

        @Override
        public int compareTo(Pair other) {
            return Integer.compare(this.fr, other.fr);
        }
    }

    static class FastInputReader {
        private final DataInputStream din;
        private final byte[] buffer;
        private int bufferPointer, bytesRead;

        public FastInputReader(InputStream in) {
            din = new DataInputStream(in);
            buffer = new byte[1 << 16]; // 64 KB buffer
            bufferPointer = bytesRead = 0;
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = 0;

            while (bufferPointer < bytesRead || refillBuffer()) {
                c = buffer[bufferPointer++];
                if (c > ' ') break; // Skip non-digit
            }

            boolean neg = (c == '-');
            if (neg) c = buffer[bufferPointer++];

            while (c >= '0' && c <= '9') {
                ret = ret * 10 + (c - '0');
                if (bufferPointer == bytesRead && !refillBuffer()) break;
                c = buffer[bufferPointer++];
            }
            return neg ? -ret : ret;
        }

        private boolean refillBuffer() throws IOException {
            bytesRead = din.read(buffer, 0, buffer.length);
            bufferPointer = 0;
            return bytesRead > 0;
        }
    }
}

• Subtask 1: 70 / 100