답안 #635281

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
635281	2022-08-25T20:59:41 Z	Anthony_Liu	Job Scheduling (CEOI12_jobs)	C++11	100 / 100	389 ms	26408 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	29 ms	2968 KB	Output is correct
2	Correct	28 ms	3048 KB	Output is correct
3	Correct	30 ms	3096 KB	Output is correct
4	Correct	29 ms	2976 KB	Output is correct
5	Correct	28 ms	2980 KB	Output is correct
6	Correct	29 ms	2980 KB	Output is correct
7	Correct	28 ms	2968 KB	Output is correct
8	Correct	28 ms	2968 KB	Output is correct
9	Correct	71 ms	9708 KB	Output is correct
10	Correct	81 ms	9820 KB	Output is correct
11	Correct	38 ms	2712 KB	Output is correct
12	Correct	76 ms	4916 KB	Output is correct
13	Correct	101 ms	8580 KB	Output is correct
14	Correct	169 ms	10820 KB	Output is correct
15	Correct	183 ms	11004 KB	Output is correct
16	Correct	243 ms	16120 KB	Output is correct
17	Correct	302 ms	18828 KB	Output is correct
18	Correct	307 ms	23216 KB	Output is correct
19	Correct	389 ms	26408 KB	Output is correct
20	Correct	292 ms	18824 KB	Output is correct