Submission #883970

#	Time	Username	Problem	Language	Result	Execution time	Memory
883970		NK_	Two Currencies (JOI23_currencies)	C++17	100 / 100	2729 ms	41120 KiB

currencies

// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>
 
using namespace std;
 
#define nl '\n'
#define pb push_back
#define sz(x) int(x.size())
 
#define f first
#define s second
#define mp make_pair
 
using ll = long long;
template<class T> using V = vector<T>;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using QRY = array<ll, 4>;
using vpi = V<pi>;
using vpl = V<pl>;
using vi = V<int>;
using vl = V<ll>;
 
const int LG = 18;
 
template<class T> struct BIT {
	int N; V<T> A; void init(int n) { N = n; A = V<T>(N, 0); };
	void upd(int p, T x) { for(++p;p<=N;p+=p&-p) A[p-1] += x; }
	T sum(int l, int r) { return sum(r + 1) - sum(l); }
	T sum(int r) { T s = 0; for(;r;r-=r&-r) s += A[r-1]; return s; }
};
 
int main() {
	cin.tie(0)->sync_with_stdio(0);
	
	int N, M, Q; cin >> N >> M >> Q;
 
	V<vpi> adj(N);
	for(int i = 0; i < N-1; i++) {
		int u, v; cin >> u >> v; --u, --v;
		adj[u].pb(mp(v, i));
		adj[v].pb(mp(u, i));
	}
 
	vpi C(M);
	for(auto& x : C) { cin >> x.s >> x.f; --x.s; }
	
	sort(begin(C), end(C));
	C.pb(mp(0, -1));
 
	V<QRY> qry(Q); 
	for(auto& x : qry) {
		cin >> x[0] >> x[1] >> x[2] >> x[3];
		--x[0], --x[1];
	}
 
	V<vi> up(N, vi(LG)); vi st(N), en(N), dep(N), EI(N-1); int t = 0;
	function<void(int, int)> gen = [&](int u, int p) {
		st[u] = t++;
		up[u][0] = p; for(int i = 1; i < LG; i++) up[u][i] = up[up[u][i-1]][i-1];
 
		for(auto& e : adj[u]) {
			auto [v, i] = e;
			if (v != p) {
				EI[i] = v; // v is the child of edge i
				dep[v] = dep[u] + 1;
				gen(v, u);
			}
		}
 
		en[u] = t - 1;
	};
 
	dep[0] = 0; gen(0, 0);
 
	auto jmp = [&](int u, int d) {
		for(int i = 0; i < LG; i++) if ((d >> i) & 1) u = up[u][i];
		return u;
	};	
 
	auto lca = [&](int a, int b) {
		if (dep[a] < dep[b]) swap(a, b);
		a = jmp(a, dep[a] - dep[b]);
 
		if (a == b) return a;
 
		for(int i = LG - 1; i >= 0; --i) {
			if (up[a][i] != up[b][i]) {
				a = up[a][i], b = up[b][i];
			}
		}
 
		return up[a][0];
	};
 
	BIT<int> B, P; BIT<ll> S; B.init(N + 1);
	for(int i = 0; i < M; i++) {
		int c, e; tie(c, e) = C[i];
		int u = EI[e];
		B.upd(st[u], 1); B.upd(en[u] + 1, -1);
	}
 
	// Parallel Binsearch
	// Largest i value that is true (LST TRUE)
	vi lo(Q, -1), hi(Q, M); vpl ans(Q, mp(-1, -1));
 
	for(int r = 0; r < LG; r++) {
		vi mid(Q); for(int i = 0; i < Q; i++) {
			if (lo[i] >= hi[i]) mid[i] = -1;
			else mid[i] = (lo[i] + hi[i] + 1) / 2;
		}
 
 		bool done = 1;
		V<vi> E(M+1); for(int i = 0; i < Q; i++) {
			if (mid[i] != -1) {
				E[mid[i]].pb(i);
				done = 0;
			}
		}

		if (done) break;
 
		S.init(N + 1), P.init(N + 1);
		for(int i = 0; i <= M; i++) {
			for(auto& idx : E[i]) { 
				int u = qry[idx][0], v = qry[idx][1], l = lca(u, v);
 
				ll s = S.sum(st[l], st[u]) + S.sum(st[l], st[v]) - 2 * S.sum(st[l], st[l]); // silver on path
				ll p = P.sum(st[l], st[u]) + P.sum(st[l], st[v]) - 2 * P.sum(st[l], st[l]); // checkpoints on path
				ll d = B.sum(st[l], st[u]) + B.sum(st[l], st[v]) - 2 * B.sum(st[l], st[l]); // checkpoints on path (all checkpoints)
				ll g = d - p;
 
				if (s <= qry[idx][3]) {
					lo[idx] = mid[idx];
					ans[idx] = mp(s, g);
				} else hi[idx] = mid[idx] - 1;
			}
 
			if (i != M) {
				int c, e; tie(c, e) = C[i];
				int u = EI[e];
				S.upd(st[u], c); S.upd(en[u] + 1, -c);
				P.upd(st[u], 1); P.upd(en[u] + 1, -1);
			}
		}
	}	
	// cout << endl << endl;
 
	for(int i = 0; i < Q; i++) {
		auto [a, b, g, s] = qry[i];
		auto [ns, ng] = ans[i];
 
		// cout << i << " ------> " << ns << " " << ng << endl;
		if (ns <= s && ng <= g) cout << g - ng << nl;
		else cout << -1 << nl;
	}
 
	exit(0-0);
}

• Subtask 1: 10 / 10
• Subtask 2: 28 / 28
• Subtask 3: 30 / 30
• Subtask 4: 32 / 32