Submission #520657

#	Time	Username	Problem	Language	Result	Execution time	Memory
520657		tkwiatkowski	Hiring (IOI09_hiring)	C++17	100 / 100	226 ms	25284 KiB

hiring

/*
	Zadanie: Hiring
	Autor: Tomasz Kwiatkowski
*/

#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back

using namespace std;
typedef long long ll;

const int MAXN = 1e6 + 7;
const int INF = 1e9 + 7;

struct frac
{
	long long p, q;
	frac () {}
	frac (long long a, long long b = 1) : p(a), q(b) {}
	bool operator==(frac x)
	{
		return p*x.q == q*x.p;
	}
	bool operator<=(frac x)
	{
		return p*x.q <= q*x.p;
	}
	bool operator<(frac x)
	{
		return p*x.q < q*x.p;
	}
	frac operator*(long long x)
	{
		return frac(p*x, q);
	}
};

int main()
{
	ios_base::sync_with_stdio(0), cin.tie(0);

	int n;
	long long w;
	cin >> n >> w;
	vector<pair<frac, int>> sorted(n);
	int i = 0;
	for (auto& [x, ind] : sorted) {
		cin >> x.p >> x.q;
		ind = i++;
	}
	vector<pair<frac, int>> candidates(sorted);
	sort(sorted.begin(), sorted.end(), [](auto lhs, auto rhs) {
		if (lhs.fi == rhs.fi) {
			if (lhs.fi.q == rhs.fi.q)
				return lhs.se < lhs.se;
			return lhs.fi.q < rhs.fi.q;
		}
		return rhs.fi < lhs.fi;
	});
	sort(candidates.begin(), candidates.end(), [](auto lhs, auto rhs) {
		if (lhs.fi.q == rhs.fi.q)
			return lhs.se < lhs.se;
		return lhs.fi.q < rhs.fi.q;
	});

	vector<bool> ok(n, true);
	int j = 0;
	int cnt = 0;
	frac money(w);
	int k = 0;
	long long sum_q = 0;
	for (auto [x, ind] : sorted) {
		if (ok[ind])
			++cnt, sum_q += x.q;
		ok[ind] = false;
		
		while (j < n && (x*(sum_q + candidates[j].fi.q*ok[candidates[j].se]) <= frac(w))) {
			sum_q += candidates[j].fi.q*ok[candidates[j].se];
			cnt += ok[candidates[j].se];
			ok[candidates[j].se] = false;
			++j;
		}
		if (x*sum_q <= frac(w)) {
			if (cnt > k)
				k = cnt, money = x*sum_q;
			else if (cnt == k && (x*sum_q < money))
				money = x*sum_q;
		}
		sum_q -= x.q;
		--cnt;
	}
	cout << k << '\n';
	ok = vector<bool>(n, true);
	vector<bool> chosen(n, false);
	j = 0;
	cnt = 0;
	sum_q = 0;
	for (auto [x, ind] : sorted) {
		if (ok[ind])
			++cnt, sum_q += x.q;
		ok[ind] = false;
		chosen[ind] = true;
		
		while (j < n && (x*(sum_q + candidates[j].fi.q*ok[candidates[j].se]) <= frac(w))) {
			if (ok[candidates[j].se])
				chosen[candidates[j].se] = true;
			sum_q += candidates[j].fi.q*ok[candidates[j].se];
			cnt += ok[candidates[j].se];
			ok[candidates[j].se] = false;
			++j;
		}
		if (x*sum_q <= frac(w) && cnt == k && (x*sum_q == money)) {
			for (int i = 0; i < n; ++i)
				if (chosen[i])
					cout << i + 1 << '\n';
			return 0;
		}
		sum_q -= x.q;
		chosen[ind] = false;
		--cnt;
	}
	return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 28 / 28
• Subtask 3: 6 / 6
• Subtask 4: 6 / 6
• Subtask 5: 6 / 6
• Subtask 6: 6 / 6
• Subtask 7: 6 / 6
• Subtask 8: 6 / 6
• Subtask 9: 6 / 6