답안 #545601

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
545601	2022-04-05T00:05:18 Z	aidan0626	Job Scheduling (CEOI12_jobs)	C++17	100 / 100	428 ms	26380 KB

jobs

#include <bits/stdc++.h>
using namespace std;

#define all(x) begin(x), end(x)
#define mp make_pair

using pi = pair<int, int>;
using vi = vector<int>;

int N, D, M;

// test if it is possible to finish the jobs using given # of machines
// return: first: possible or not, second: if possible, the schedule for the jobs
pair<bool, vector<vi>> isFeasible(const vector<pi> &jobs, int machineCount)
{
	vector<vi> schedule(N);
	int reqNum = 0;
	// we simulate from day 1 until the last day N
	// we move to the next day if all the machines are used or
	// there is no more job requests left on or before this day
	for (int day = 1; day <= N; day++)
	{
		for (int j = 0; j < machineCount; j++)
		{
			// if all jobs before and on this day are finished,
			// we can go to the next day, even if there are usable machines left
			// we can determine that since the vector jobs is sorted
			if (jobs[reqNum].first > day)
				break;
			// if the current date is before the deadline for the job
			// we can add this job to the schedule and move to the next job request
			if (jobs[reqNum].first + D >= day)
				schedule[day - 1].push_back(jobs[reqNum++].second);
			// otherwise, it is not feasible due to deadline
			else
				return mp(false, schedule);

			// if we have processed all the requests, we have found a feasible sol
			if (reqNum == M)
				return mp(true, schedule);
		}
	}
	// if not all the requests can be processed within the given N days,
	// then it is not feasible
	return mp(false, schedule);
}

int main()
{
	cin.tie(0)->sync_with_stdio(false);

	cin >> N >> D >> M;
	vector<pi> jobs(M);
	for (int i = 0; i < M; i++)
	{
		int day;
		cin >> day;
		// first: request date, second: index [1..M]
		jobs[i] = mp(day, i + 1);
	}
	// we sort the jobs by the request date in ascending order
	// sothat we can test them using isFeasible() in linear time whether they
	// can be done in given time using a certain amount of machines
	sort(all(jobs));

	vector<vi> result;
	// binary search on the number of machines for the minimum possible solution
	// left and right bound, l and r
	int l = 1, r = M;
	while (l < r)
	{
		int machineNum = (l + r) / 2;
		// test if the jobs would finish within the deadline
		// using the current # of machines, machineNum
		pair<bool, vector<vi>> curResult = isFeasible(jobs, machineNum);
		// if it's possible, we set the right bound as the tested machine number
		// and save the current schedule
		if (curResult.first)
		{
			r = machineNum;
			result = curResult.second;
		}
		// otherwise, we set the left bound to be the tested number + 1
		// and test the next machineNum again
		else
			l = machineNum + 1;
	}

	cout << l << "\n";
	for (int i = 0; i < N; i++)
	{
		for (int &idx : result[i])
			cout << idx << " ";
		cout << 0 << "\n";
	}
}

Subtask #1

100.0 / 100.0

#	결과	실행 시간	메모리	Grader output
1	Correct	30 ms	2968 KB	Output is correct
2	Correct	32 ms	3104 KB	Output is correct
3	Correct	31 ms	3024 KB	Output is correct
4	Correct	31 ms	2972 KB	Output is correct
5	Correct	31 ms	2968 KB	Output is correct
6	Correct	37 ms	2972 KB	Output is correct
7	Correct	33 ms	3060 KB	Output is correct
8	Correct	30 ms	2976 KB	Output is correct
9	Correct	79 ms	9688 KB	Output is correct
10	Correct	87 ms	9704 KB	Output is correct
11	Correct	39 ms	2748 KB	Output is correct
12	Correct	76 ms	5024 KB	Output is correct
13	Correct	119 ms	8564 KB	Output is correct
14	Correct	193 ms	10824 KB	Output is correct
15	Correct	201 ms	10944 KB	Output is correct
16	Correct	266 ms	16156 KB	Output is correct
17	Correct	308 ms	18728 KB	Output is correct
18	Correct	353 ms	23320 KB	Output is correct
19	Correct	428 ms	26380 KB	Output is correct
20	Correct	325 ms	18728 KB	Output is correct