Submission #964988

#	Time	Username	Problem	Language	Result	Execution time	Memory
964988		fzyzzz_z	Hiring (IOI09_hiring)	C++17	100 / 100	541 ms	21696 KiB

hiring

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

using ll = long long; 
#define fs first
#define sc second 

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n; 
	ll k; 
	cin >> n >> k; 
	vector<pair<int, int>> a(n); 
	vector<int> ord(n); 

	for (int i = 0; i < n; ++i) {
		cin >> a[i].sc >> a[i].fs; 
		ord[i] = i; 
	}

	sort(ord.begin(), ord.end(), [&](int & x, int & y){
		if (a[x].fs * a[y].sc == a[x].sc * a[y].fs) return a[x].sc < a[y].sc; 
		return (a[y].fs * a[x].sc <= a[y].sc * a[x].fs); 
	});

	set<pair<int, int>> st; 
	int ans = 0, at = 0; 
	ll cs = 0; 
	ll tcb = 1, tct = 0; 

	for (int i = 0; i < n; ++i) {
		int x = a[ord[i]].fs, y = a[ord[i]].sc; 
		cs += x; 
		st.insert({x, i}); 

		while (cs * y > k * x) {
			pair<int, int> v = *st.rbegin(); 
			cs -= v.fs; 
			st.erase(v); 
		}

		if (st.size() > ans) {
			ans = st.size(); 
			tct = cs * y; 
			tcb = x; 
			at = i; 
		} else if (cs * y * tcb < tct * x && st.size() == ans) {
			tct = cs * y; 
			tcb = x; 
			at = i; 
		}
	}

	st.clear(); 
	cs = 0; 
	for (int i = 0; i < n; ++i) {
		int x = a[ord[i]].fs, y = a[ord[i]].sc; 
		cs += x; 
		st.insert({x, ord[i]}); 

		while (cs * y > k * x) {
			pair<int, int> v = *st.rbegin(); 
			cs -= v.fs; 
			st.erase(v); 
		}

		if (at == i) {
			cout << ans << "\n";
			for (auto v: st) {
				cout << v.sc + 1 << "\n"; 
			}
			return 0; 
		}
	}

	assert(false); 

	return 0; 
}

Compilation message (stderr)

hiring.cpp: In function 'int main()':
hiring.cpp:44:17: warning: comparison of integer expressions of different signedness: 'std::set<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   44 |   if (st.size() > ans) {
      |       ~~~~~~~~~~^~~~~
hiring.cpp:49:50: warning: comparison of integer expressions of different signedness: 'std::set<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   49 |   } else if (cs * y * tcb < tct * x && st.size() == ans) {
      |                                        ~~~~~~~~~~^~~~~~

• 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