Submission #1052741

#	Time	Username	Problem	Language	Result	Execution time	Memory
1052741		Nonoze	Fire (BOI24_fire)	C++17	100 / 100	287 ms	91796 KiB

Main

/*
*	Author: Nonoze
*	Created: Monday 06/05/2024
*/
#include <bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T> using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long ll;
#define int long long


#ifdef _IN_LOCAL
	#include <bits/DebugTemplate.h>
#else
	#define dbg(...) ;
#endif
#define sz(x) (int)(x.size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define pb push_back
#define mp make_pair
#define fi first
#define se second

#define endl '\n'
#define endlfl '\n' << flush
#define quit(x) {cout << x << endl; return;}
#define cmin(a, b) a = min(a, b)
#define cmax(a, b) a = max(a, b)
const int inf = numeric_limits<int>::max() / 4;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1e9+7, LOG=25;



void solve();

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tt=1;
	// cin >> tt;
	while(tt--) solve();
	return 0;
}




int n, m, q;
vector<pair<int, int>> a;
vector<int> memo, nxt;
int first=0;

vector<vector<int>> sparce;
vector<int> logs;

void init() {
	vector<int> vec;
	for (int i=0; i<n; i++) vec.pb(a[i].fi);
	logs.clear(), logs.resize(n+1); logs[0]=0, logs[1]=0;
	for (int i=2; i<=n; i++) logs[i]=logs[i/2]+1;
	int lg=logs[n]+1;
	sparce.clear(), sparce.resize(lg, vector<int>(n, inf));
	for (int i=0; i<n; i++) sparce[0][i]=vec[i];
	for (int i=1; i<lg; i++) {
		for (int j=0; j+(1<<i)<=n; j++) {
			sparce[i][j]=min(sparce[i-1][j], sparce[i-1][j+(1<<(i-1))]);
		}
	}
}

int query(int l, int r) {
	int lg=logs[r-l+1];
	return min(sparce[lg][l], sparce[lg][r-(1<<lg)+1]);
}

vector<vector<int>> up;
vector<int> depth;
vector<bool> did;

void dfs(int s) {
	if (s>=n || did[s]) return;
	did[s]=1;
	dfs(nxt[s]);
	up[s][0]=nxt[s];
	depth[s]=depth[nxt[s]]+1;
	for (int i=1; i<LOG; i++) {
		up[s][i]=up[up[s][i-1]][i-1];
	}
}

int kth(int s, int k) {
	for (int i=0; i<LOG; i++) {
		if (k&(1<<i)) s=up[s][i];
	}
	return s;
}

void solve() {
	cin >> n >> m;
	a.clear(), a.resize(n), nxt.resize(n);
	for (auto &u: a) {
		cin >> u.fi >> u.se;
		if (u.se<u.fi) u.se+=m;
	}
	sort(all(a), [&](pair<int, int> &x, pair<int, int> &y) {
		return x.se < y.se;
	});
	init();
	for (int i=n-1; i>=0; i--) {
		int l=i+1, r=n-1, ans=n;
		while (l<=r) {
			int mid=(l+r)/2;
			if (query(mid, r)<=a[i].se) {
				ans=mid;
				l=mid+1;
			} else r=mid-1;
		}
		nxt[i]=ans;
	}
	up.resize(n+1, vector<int>(LOG, n)), did.resize(n, 0), depth.resize(n+1, 0);
	for (int i=0; i<n; i++) dfs(i);
	int ans=inf;
	for (int i=0; i<n; i++) {
		int objective=a[i].fi+m;
		int l=1, r=depth[i]-1, res=inf;
		while (l<=r) {
			int mid=(l+r)/2;
			if (a[kth(i, mid)].se>=objective) {
				res=mid;
				r=mid-1;
			} else l=mid+1;
		}
		cmin(ans, res+1);
	}
	if (ans!=inf) cout << ans << endl;
	else cout << -1 << endl;
}

• Subtask 1: 14 / 14
• Subtask 2: 17 / 17
• Subtask 3: 9 / 9
• Subtask 4: 13 / 13
• Subtask 5: 21 / 21
• Subtask 6: 26 / 26