Submission #838368

#	Time	Username	Problem	Language	Result	Execution time	Memory
838368		mat_jur	Toll (BOI17_toll)	C++17	7 / 100	30 ms	7048 KiB

toll

#include <bits/stdc++.h>
#include <cassert>
using namespace std;
#ifdef DEBUG
auto&operator<<(auto &o, pair<auto, auto> p) {o << "(" << p.first << ", " << p.second << ")"; return o;}
auto operator<<(auto &o, auto x)->decltype(x.end(), o) {o<<"{"; for(auto e : x) o<<e<<", "; return o<<"}";}
#define debug(X) cerr << "["#X"]: " << X << '\n';
#else 
#define debug(X) ;
#endif
#define ll long long
#define all(v) (v).begin(), (v).end()
#define FOR(i,l,r) for(int i=(l);i<=(r);++i)
#define ROF(i,r,l) for(int i=(r);i>=(l);--i)
#define REP(i,n) FOR(i,0,(n)-1)
#define ssize(x) int(x.size())
#define fi first
#define se second

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	int k, n, m, o;
	cin >> k >> n >> m >> o;
	vector<vector<pair<int, int>>> G(n), odwr(n);
	REP(i, m) {
		int a, b, t;
		cin >> a >> b >> t;
		G[a].push_back({b, t});
		odwr[b].push_back({a, t});
	}
	constexpr int inf = 1e9;
	vector<int> a(o), b(o);
	vector<int> Q, ans(o, inf);
	REP(i, o) {
		cin >> a[i] >> b[i];
		Q.push_back(i);
	}
	vector lef(k, vector(n, inf)), rig(k, vector(n, inf));
	function<void(int, int, vector<int>)> solve = [&](int l, int r, vector<int> v) {
		if (v.size() == 0) return;
		if (l == r) {
			for (auto e : v) ans[e] = (a[e]==b[e]?0:inf);
			return;
		}
		int mid = (l+r)/2;
		REP(j, k) {
			lef[j][k*mid+j] = rig[j][k*mid+j] = 0;
			ROF(i, mid*k-1, l*k) {
				lef[j][i] = inf;
				for (auto w : G[i]) {
					lef[j][i] = min(lef[j][i], w.se+lef[j][w.fi]);
				}
			}
			FOR(i, (mid+1)*k, min(r*k+k-1, n-1)) {
				rig[j][i] = inf;
				for (auto w : odwr[i]) {
					rig[j][i] = min(rig[j][i], w.se+rig[j][w.fi]);
				}
			}
		}
		vector<int> todo[2];
		for (auto e : v) {
			int A = a[e], B = b[e];
			assert(A >= l*k && r <= min(r*k+k-1, n-1));
			if (A/k <= mid && mid < B/k) {
				REP(i, k) {
					ans[e] = min(ans[e], lef[i][A]+rig[i][B]);	
				}
				continue;
			}
			todo[B/k > mid].push_back(e);
		}
		solve(l, mid, todo[0]); solve(mid+1, r, todo[1]);
	};
	solve(0, (n-1)/k, Q);
	REP(i, o) cout << (ans[i]==inf?-1:ans[i]) << '\n';

	return 0;
};

• Subtask 1: 7 / 7
• Subtask 2: 0 / 10
• Subtask 3: 0 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44