Submission #816871

#	Time	Username	Problem	Language	Result	Execution time	Memory
816871		AlphaBruh	Radio Towers (IOI22_towers)	C++17	0 / 100	4059 ms	4828 KiB

towers

#include "towers.h"
#include <vector>
#include<bits/stdc++.h>
using namespace std;
#define inf 2e9
vector<int>hs;
struct bd{
	int h=-1, id=0;
	bool operator>(bd a){
		return h > a.h;
	}
};
bd tree[350000];
bd bdmx(bd a, bd b){
	if(a.h>b.h) return a;
	return b;
}
int n,d;
void build(int l, int r,int id){
	if(l==r){
		tree[id].h=hs[l];
		tree[id].id=l;
		return;
	}
	int m = (l+r)>>1;
	build(l,m,id*2);
	build(m+1,r,id*2+1);
	tree[id] = bdmx(tree[id*2],tree[id*2+1]);
	return;
}
bd get_max(int l, int r, int s, int e, int id){
	if(s <= l && r <=e){
		return tree[id];
	}
	int m = (l+r)>>1;
	bd mx;
	if(s<=m){
		mx = bdmx(mx,get_max(l,m,s,e,id*2));
	}
	if(m+1<=e){
		mx = bdmx(mx,get_max(m+1,r,s,e,id*2+1));
	}
	return mx;
}
vector<int>mxid(200005,-1);
int rent_max(int l, int r, int lmh,int from,int lor){
	//printf("%d %d %d\n",l,r,lmh);
	if(l>r) return 0;
	if(l==r){
		if(lmh >= hs[l]){
			return 1;
		}
		return 0;
	}
	bd mxb;
	if(lor==-1 || mxid[from*2+lor]==-1){
		mxb = get_max(0,n-1,l,r,1);
		mxid[from*2+lor]=mxb.id;
	}
	else{
		mxb.id = mxid[from*2+lor];
		mxb.h = hs[mxb.id];
	}
	int lm = rent_max(l,mxb.id-1,mxb.h-d,mxb.id,0);
	int rm = rent_max(mxb.id+1,r,mxb.h-d,mxb.id,1);
	int be = lm+rm, nbe;
	nbe = max(lm,rm);
	return max(max(be,nbe),1);
}
void init(int N, std::vector<int> H) {
	n=N;
	hs.assign(H.begin(),H.end());
	build(0,N-1,1);
}

int max_towers(int L, int R, int D) {
	d=D;
	return rent_max(L,R,inf,n,-1);
}

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