Submission #511278

#	Time	Username	Problem	Language	Result	Execution time	Memory
511278		akhan42	Toll (BOI17_toll)	C++17	100 / 100	359 ms	56832 KiB

toll

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
//using namespace __gnu_pbds;

#define F first
#define S second
#define forn(i, n) for(int i = 0; i < n; ++i)
#define forbn(i, b, n) for(int i = b; i < n; ++i)
#define sz(v) (int)v.size()
#define pb push_back
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define mp make_pair

typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef long long ll;
//typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

template <class T> inline void mineq(T &a, T b) { a = min(a, b); }
template <class T> inline void maxeq(T &a, T b) { a = max(a, b); }


const int INF = 1000 * 1000 * 1000;
const int MX = 50 * 1000 + 10;
const int mxpw = 20;
int k, n, m, o;

vii gr[MX][mxpw];


void next_pos(vii& positions, vii& npositions, int pw) {
	vi mns(k, INF);
	int fac = -1;
	for(ii pos_t: positions) {
		int pos = pos_t.F, t = pos_t.S;
		for(ii nb2_t: gr[pos][pw]) {
			int nb2 = nb2_t.F, t2 = nb2_t.S;

			mineq(mns[nb2 % k], t + t2);
			fac = nb2 / k;
		}
	}
	npositions.clear();
	forn(t, k) {
		if(mns[t] != INF) {
			npositions.eb(k * fac + t, mns[t]);
		}
	}
}

void solve() {
	cin >> k >> n >> m >> o;
	forn(_, m) {
		int a, b, t;
		cin >> a >> b >> t;

		gr[a][0].eb(b, t);
	}

	forbn(d, 1, mxpw)
		forn(a, n)
			next_pos(gr[a][d - 1], gr[a][d], d - 1);

	forn(_, o) {
		int a, b;
		cin >> a >> b;

		bool printed = false;
		int diff = b / k - a / k;
		if(diff >= 0) {
			vii positions;
			positions.eb(a, 0);

			for(int pw = 0; diff; pw++, diff >>= 1)
				if(diff & 1)
					next_pos(positions, positions, pw);

			for(ii pos: positions) {
				if(pos.F == b) {
					cout << pos.S << '\n';
					printed = true;
				}
			}
		}

		if(!printed)
			cout << -1 << '\n';
	}
}


int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
//	cout.tie(nullptr);

//	freopen("262144.in", "r", stdin);
//	freopen("262144.out", "w", stdout);

	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