AcWing 1241. 外卖店优先级 (模拟)

Problem

这个题是第十届也就是这次比赛好像是第六题还是第七题，是一道模拟外卖系统的题目，题目描述很简单，有外卖就加分，没有减分，分数大进缓存系统，少了出系统，模拟就可以，但是数据量有点大，单单的暴力模拟最后的满数据过不了。

优化方法是将相同订单批次处理。

AC代码：

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

class Main {
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    static PrintWriter pw = new PrintWriter(System.out);
    static int n, m, t;
    static int score[], last[]; //last[] 记录上次订单时间
    static boolean inlist[]; //inlist[]记录是否在优先缓存中

    public static void main(String[] args) throws IOException {
        String[] s = br.readLine().split(" ");
        n = Integer.parseInt(s[0]);
        m = Integer.parseInt(s[1]);
        t = Integer.parseInt(s[2]);
        Point p[] = new Point[m];
        score = new int[n + 1];
        last = new int[n + 1];
        inlist = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            s = br.readLine().split(" ");
            p[i] = new Point(Integer.parseInt(s[0]), Integer.parseInt(s[1]));
        }
        Arrays.sort(p);


        for (int i = 0; i < m; ) {
            int j = i;
            while (j < m && p[i].getTime() == p[j].getTime() && p[i].getId() == p[j].getId()) j++;
            int time = p[i].getTime(), id = p[i].getId(), cnt = j - i;
            i = j;

            score[id] -= time - last[id] - 1;
            if (score[id] < 0) score[id] = 0;
            if (score[id] <= 3) inlist[id] = false;

            score[id] += cnt * 2;
            if (score[id] > 5) inlist[id] = true;

            last[id] = time;
        }

        for (int i = 1; i <= n; i++) {
            if (last[i] < t) {
                score[i] -= t - last[i];
                if (score[i] <= 3) inlist[i] = false;
            }
        }
        int res = 0;
        for (int i = 1; i <= n; i++) {
            if (inlist[i]) res++;
        }
        pw.print(res);
        pw.flush();
        pw.close();
        br.close();

    }
}

class Point implements Comparable<Point> {
    private int time;
    private int id;

    public int getTime() {
        return time;
    }

    public int getId() {
        return id;
    }

    public Point(int time, int id) {
        this.time = time;
        this.id = id;
    }

    @Override
    public int compareTo(Point p) {
        if (this.getTime() == p.getTime()) return this.getId() - p.getId();
        return this.getTime() - p.getTime();
    }
}

这边给出暴力的模拟代码 ：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.PriorityQueue;

public class Main {
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    static PrintWriter pw = new PrintWriter(System.out);
    static int n, m, t;
    static int p[];
    static boolean inlist[], ifNew[];
    static PriorityQueue<Time> queue = new PriorityQueue<>(new Comparator<Time>() {
        @Override
        public int compare(Time time, Time t1) {
            return time.getMin() - t1.getMin();
        }
    });

    public static void main(String[] args) throws NumberFormatException, IOException {

        String s[] = br.readLine().split(" ");
        n = Integer.parseInt(s[0]);
        m = Integer.parseInt(s[1]);
        t = Integer.parseInt(s[2]);
        inlist = new boolean[n + 1];
        ifNew = new boolean[n + 1];
        p = new int[n + 1];
        for (int i = 0; i < m; i++) {
            s = br.readLine().split(" ");
            queue.offer(new Time(Integer.parseInt(s[0]), Integer.parseInt(s[1])));
        }
        for (int i = 1; i <= t; i++) {

            if (i > m && i == t) {
                int sum = 0;
                for (int j = 1; j <= n; j++) {
                    if (inlist[j]) sum++;
                }
                pw.print(sum);
            }

            if (i > m) {
                for (int k = 1; k <= n; k++) {
                    if (p[k] > 0) p[k]--;
                }
                continue;
            }

            while (!queue.isEmpty()) {
                Time temp = queue.peek();
                if (temp.getMin() == i) {
                    int num = temp.getNum();
                    p[num] += 2;
                    ifNew[num] = true;
                } else break;
                queue.poll();
            }
            for (int j = 1; j <= n; j++) {
                if (!ifNew[j]) {
                    if (p[j] > 0)
                        p[j]--;
                }
                if (p[j] > 5) inlist[j] = true;
                if (p[j] <= 3) inlist[j] = false;
            }
            Arrays.fill(ifNew, false);

            if (i == t) {
                int sum = 0;
                for (int j = 1; j <= n; j++) {
                    if (inlist[j]) sum++;
                }
                pw.print(sum);
                break;
            }
        }
        pw.flush();
        pw.close();
        br.close();
    }
}

class Time {
    int min;
    int num;

    public int getMin() {
        return min;
    }

    public void setMin(int min) {
        this.min = min;
    }

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    public Time(int min, int num) {
        this.min = min;
        this.num = num;
    }
}