Submission #567698

#	Time	Username	Problem	Language	Result	Execution time	Memory
567698		_karan_gandhi	Toll (BOI17_toll)	C++17	100 / 100	165 ms	198820 KiB

toll

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

#define all(v) v.begin(), v.end()
#define endl '\n'
#define pl(var) " [" << #var << ": " << (var) << "] "
#define ll long long

void solve() {
	ll int k, n, m, o; cin >> k >> n >> m >> o;

	const ll int LOG = 20;
	// dp[i][i + 2 ^ k][x][y];
	ll int dp[n / k][LOG][5][5];
	memset(dp, 1, sizeof dp);

	vector<vector<pair<ll int, ll int>>> adj(n);

	for (ll int i = 0; i < m; i++) {
		ll int a, b; cin >> a >> b;
		ll int c; cin >> c;

		adj[a].emplace_back(b, c);
	}

	for (ll int i = 0; i < n; i++) {
		for (auto [v, wt] : adj[i]) {
			dp[i / k][0][i % k][v % k] = wt;
		}
	}

	auto combine = [&](ll int target[5][5], ll int a[5][5], ll int b[5][5]) {
		for (ll int i = 0; i < k; i++) {
			for (ll int j = 0; j < k; j++) {
				for (ll int l = 0; l < k; l++) {
					target[i][j] = min(target[i][j], a[i][l] + b[l][j]);
				}
			}
		}
	};

	for (ll int i = 1; i < LOG; i++) {
		for (ll int j = 0; j < n / k; j++) {
			if (j + (1 << (i - 1)) >= n / k) continue;
			combine(dp[j][i], dp[j][i - 1], dp[j + (1 << (i - 1))][i - 1]);
		}
	}

	// TODO: write query again

	auto query = [&](ll int start, ll int end) {
		ll int res[5][5];
		memset(res, 1, sizeof res);
		for (int i = 0; i < 5; i++) res[i][i] = 0;
		ll int level = start / k;
		ll int target = end / k;
		int pow = LOG;

		while (level != target) {
			while (level + (1 << pow) > target) pow--;
	
			ll int new_res[5][5];
			memset(new_res, 1, sizeof new_res);

			combine(new_res, res, dp[level][pow]);
			memcpy(res, new_res, sizeof res);

			level += (1 << pow);
		}

		return res[start % k][end % k];
	};

	while (o--) {
		int a, b; cin >> a >> b;

		ll int res = query(a, b);

		if (res > 1e16) cout << -1 << endl;
		else cout << res << endl;
	}
}

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

	ll int T = 1;
	// cin >> T;
	while (T--)
		solve();
}

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 31 / 31
• Subtask 5: 44 / 44