Submission #1123502

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123502		Pwo	Trains (BOI24_trains)	C++17	34 / 100	32 ms	10176 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int m = 1e9 + 7;

int n, dp[100005];
pair<int, int> a[100005];
vector<int> v;
unordered_map<int, int> tmp;
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
unordered_map<int, int> rem[100005];

int32_t main() {
	ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> a[i].first >> a[i].second;
	dp[1] = 1;

	for (int i = 1; i <= n; i++) {
		if (a[i].first == 0) continue;
		if (tmp.find(a[i].first) == tmp.end()) {
			tmp[a[i].first] = v.size();
			v.push_back(a[i].first);
		}
	}
	
	if (a[1].first == 0 || a[1].second == 0) {
		cout << 0;
		return 0;
	}

	rem[0][1 % a[1].first] = 1;
	pq.emplace(a[1].second * a[1].first + 1, 1);
	for (int i = 2; i <= n; i++) {
		while (!pq.empty() && pq.top().first < i) {
			int idx = pq.top().second;
			int k = tmp[a[idx].first];
			int r = idx % a[idx].first;
			rem[k][r] = (rem[k][r] - dp[idx] + m) % m;
			pq.pop();
		}
		
		for (size_t j = 0; j < v.size(); j++) {
			int r = i % v[j];
			dp[i] = (dp[i] + rem[j][r]) % m;
		}

		if (a[i].first > 0) {
			int idx = tmp[a[i].first];
			int r = i % a[i].first;
			rem[idx][r] = (rem[idx][r] + dp[i]) % m;
			pq.emplace(a[i].second * a[i].first + i, i);
		}
	}

	int ans = 0;
	for (int i = 1; i <= n; i++) ans = (ans + dp[i]) % m;
	cout << ans;
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 13
• Subtask 3: 0 / 16
• Subtask 4: 34 / 34
• Subtask 5: 0 / 29