Submission #1312310

#	Time	Username	Problem	Language	Result	Execution time	Memory
1312310		ByeWorld	Radio Towers (IOI22_towers)	C++20	23 / 100	4070 ms	5024 KiB

towers

#include "towers.h"
#include <bits/stdc++.h>
#define ll long long
#define fi first 
#define se second
#define pb push_back
#define lf ((id)<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
using namespace std;
typedef pair<ll,ll> pii;
typedef pair<ll,pii> ipii;
const int MAXN = 3e5+100;
const int LOG = 19;
const ll INF = 2e18+10;
const int INF2 = 2e9+10;
void chmx(auto &a, auto b){ a = max(a, b); }
void chmn(auto &a, auto b){ a = min(a, b); }

int n, h[MAXN];

struct seg {
	int st[4*MAXN];
	void bd(int id,int l,int r){
		if(l==r){
			st[id] = h[l]; return;
		}
		bd(lf,l,md); bd(rg,md+1,r);
		st[id] = max(st[lf], st[rg]);
	}
	int upd(int id,int l,int r,int x,int y){
		if(l==r && l==x) return st[id] = y;
		if(r<x || x<l) return st[id];
		return st[id] = max(upd(lf,l,md,x,y), upd(rg,md+1,r,x,y));
	}
	int que(int id,int l,int r,int x,int y){
		if(x<=l && r<=y) return st[id];
		if(r<x || y<l) return 0;
		return max(que(lf,l,md,x,y), que(rg,md+1,r,x,y));
	}
} A, B;
void init(int N, std::vector<int> H) {
	n = N;
	for(int i=1; i<=n; i++){
		h[i] = H[i-1];
	}
	B.bd(1,1,n);
}
int dp[MAXN];

int max_towers(int L, int R, int D) {
	int l = L+1, r = R+1, d = D;
	if(l==r || l+1==r) return 1;

	priority_queue<pii, vector<pii>, greater<pii>> pq;

	for(int i=L+1; i<=R+1; i++){
		while(!pq.empty() && pq.top().fi+d <= h[i]){
			int id = pq.top().se;
			A.upd(1,1,n,id, dp[id]);
			pq.pop();
		}
		pq.push({h[i], i});

		int l=1, r=i-1, mid=0, cnt=-1;
		while(l<=r){
			mid = md;
			if(B.que(1,1,n,mid,i-1) >= h[i]+d){
				cnt = mid; l = mid+1;
			} else r = mid-1;
		}
		dp[i] = 1;
		if(cnt != -1) dp[i] = A.que(1,1,n,1,cnt-1)+1;
	}
	int ANS = 0;
	for(int i=L+1; i<=R+1; i++) chmx(ANS, dp[i]);
	return ANS;
}

• Subtask 1: 0 / 4
• Subtask 2: 11 / 11
• Subtask 3: 12 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 17
• Subtask 6: 0 / 19
• Subtask 7: 0 / 23