Submission #577473

#	Time	Username	Problem	Language	Result	Execution time	Memory
577473		cheissmart	Railway Trip 2 (JOI22_ho_t4)	C++14	100 / 100	1359 ms	172496 KiB

Main

#include <bits/stdc++.h>
#define IO_OP std::ios::sync_with_stdio(0); std::cin.tie(0);
#define F first
#define S second
#define V vector
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(), (v).end()

using namespace std;

typedef long long ll;
typedef pair<int, int> pi;
typedef V<int> vi;

string _reset = "\u001b[0m", _yellow = "\u001b[33m", _bold = "\u001b[1m";
void DBG() { cerr << "]" << _reset << endl; }
template<class H, class...T> void DBG(H h, T ...t) {
	cerr << to_string(h);
	if(sizeof ...(t)) cerr << ", ";
	DBG(t...);
}
#ifdef CHEISSMART
#define debug(...) cerr << _yellow << _bold << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define debug(...)
#endif

const int INF = 1e9 + 7, N = 1e5 + 7;

vi rig[N], lef[N];
vi ls[20], rs[20];

int n;

struct segtree {
	pi t[N * 4]; // min, max
	vi a;
	void init(vi _a) {
		a = _a;
		assert(SZ(a) == n);
		build();
	}
	void pull(int v) {
		t[v].F = min(t[v * 2].F, t[v * 2 + 1].F);
		t[v].S = max(t[v * 2].S, t[v * 2 + 1].S);
	}
	void build(int v = 1, int tl = 0, int tr = n) {
		if(tr - tl == 1) {
			t[v] = {a[tl], a[tl]};
			return;
		}
		int tm = (tl + tr) / 2;
		build(v * 2, tl, tm);
		build(v * 2 + 1, tm, tr);
		pull(v);
	}
	int qry_min(int l, int r, int v = 1, int tl = 0, int tr = n) {
		if(l <= tl && tr <= r)
			return t[v].F;
		int tm = (tl + tr) / 2, ans = INF;
		if(l < tm) ans = min(ans, qry_min(l, r, v * 2, tl, tm));
		if(r > tm) ans = min(ans, qry_min(l, r, v * 2 + 1, tm, tr));
		return ans;
	}
	int qry_max(int l, int r, int v = 1, int tl = 0, int tr = n) {
		if(l <= tl && tr <= r)
			return t[v].S;
		int tm = (tl + tr) / 2, ans = -INF;
		if(l < tm) ans = max(ans, qry_max(l, r, v * 2, tl, tm));
		if(r > tm) ans = max(ans, qry_max(l, r, v * 2 + 1, tm, tr));
		return ans;
	}
} lt[20], rt[20];

signed main()
{
	IO_OP;

	int k, m;
	cin >> n >> k >> m;

	for(int i = 0; i < m; i++) {
		int a, b;
		cin >> a >> b, a--, b--;
		if(a < b) {
			rig[a].PB(b);
		} else {
			lef[a].PB(b);
		}
	}

	vi l(n), r(n);

	{
		multiset<int> s;
		for(int i = 0; i < n; i++) {
			for(int j:rig[i])
				s.insert(j);
			if(i - k >= 0)  for(int j:rig[i - k])
				s.erase(s.find(j));
			r[i] = i;
			if(s.size()) r[i] = max(r[i], *s.rbegin());
		}
	}
	{
		multiset<int> s;
		for(int i = n - 1; i >= 0; i--) {
			for(int j:lef[i])
				s.insert(j);
			if(i + k < n)  for(int j:lef[i + k])
				s.erase(s.find(j));
			l[i] = i;
			if(s.size()) l[i] = min(l[i], *s.begin());
		}	
	}

	auto go = [&] (int k) {
		ls[k] = l, rs[k] = r;
		lt[k].init(l), rt[k].init(r);
	};
	go(0);

	for(int k = 1; k < 20; k++) {
		l.clear(), r.clear();
		for(int i = 0; i < n; i++) {
			l.PB(lt[k - 1].qry_min(ls[k - 1][i], rs[k - 1][i] + 1));
			r.PB(rt[k - 1].qry_max(ls[k - 1][i], rs[k - 1][i] + 1));
		}
		go(k);
	}

	int q;
	cin >> q;
	while(q--) {
		int s, t;
		cin >> s >> t, s--, t--;
		assert(s != t);
		int l = s, r = s, ans = 0;
		for(int i = 19; i >= 0; i--) {
			int new_l = lt[i].qry_min(l, r + 1);
			int new_r = rt[i].qry_max(l, r + 1);
			if(new_l <= t && t <= new_r) continue;
			ans += 1 << i;
			l = new_l, r = new_r;
		}
		int new_l = lt[0].qry_min(l, r + 1);
		int new_r = rt[0].qry_max(l, r + 1);
		l = new_l, r = new_r;
		ans++;
		
		if(l <= t && t <= r) {
			cout << ans << '\n';
		} else {
			cout << -1 << '\n';
		}
	}

}

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 11 / 11
• Subtask 4: 25 / 25
• Subtask 5: 35 / 35
• Subtask 6: 13 / 13