Submission #626100

#	Time	Username	Problem	Language	Result	Execution time	Memory
626100		errorgorn	Radio Towers (IOI22_towers)	C++17	56 / 100	1475 ms	79852 KiB

towers

#include "towers.h"
 
#include <bits/stdc++.h>
using namespace std;
 
#define int long long
#define ii pair<int,int>
#define fi first
#define se second
 
#define puf push_front
#define pof pop_front
#define pub push_back
#define pob pop_back
#define lb lower_bound
#define ub upper_bound
 
#define rep(x,s,e) for (int x=(s)-((s)>(e));x!=(e)-((s)>(e));((s)<(e))?x++:x--)
#define all(x) (x).begin(),(x).end()
#define sz(x) (int) (x).size()
 
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
 
struct dat{
	int mn,mx;
	int a,b;
 
	dat(){};
 
	dat (int i){
		mn=mx=i;
		a=b=0;
	}
};
 
dat merge(dat a,dat b){
	dat res;
	res.mn=min(a.mn,b.mn);
	res.mx=max(a.mx,b.mx);
	res.a=max({a.a,b.a,a.mx-b.mn});
	res.b=max({a.b,b.b,b.mx-a.mn});
	return res;
}
 
struct node{
	int s,e,m;
	dat val;
	node *l,*r;
 
	node (int _s,int _e){
		s=_s,e=_e,m=s+e>>1;
 
		if (s!=e){
			l=new node(s,m);
			r=new node(m+1,e);
		}
	}
 
	void update(int i,int k){
		if (s==e) val=dat(k);
		else{
			if (i<=m) l->update(i,k);
			else r->update(i,k);
 
			val=merge(l->val,r->val);
		}
	}
 
	dat query(int i,int j){
		if (s==i && e==j) return val;
		else if (j<=m) return l->query(i,j);
		else if (m<i) return r->query(i,j);
		else return merge(l->query(i,m),r->query(m+1,j));
	}
} *root=new node(0,100005);
 
int n;
int arr[100005];
 
void init(signed N, vector<signed> H) {
	n=N;
	rep(x,0,n) arr[x+1]=H[x];
 
	rep(x,1,n+1) root->update(x,arr[x]);
}
 
bool proc=false;
ii tkd[200005][20]; //(nxt,score)
 
signed max_towers(signed l, signed r, signed d) {
	if (l==r) return 1;
	l++,r++; //0-based indexing is cringe
 
	if (!proc){
		memset(tkd,-1,sizeof(tkd));
 
		int r=n+1;
		rep(x,n+1,1){
			while (x<r && root->query(x,r-1).a>=d) r--;
			if (r!=n+1) tkd[x*2][0]={2*r+1,1};
		}
 
		r=n+1;
		rep(x,n+1,1){
			while (x<r && root->query(x,r-1).b>=d) r--;
			if (r!=n+1) tkd[x*2+1][0]={2*r,0};
		}
 
		rep(layer,0,19){
			rep(x,0,200005) if (tkd[x][layer].fi!=-1){
				int nxt=tkd[x][layer].fi;
				if (tkd[nxt][layer].fi==-1) continue;
 
				tkd[x][layer+1]={tkd[nxt][layer].fi,tkd[x][layer].se+tkd[nxt][layer].se};
			}
		}
 
		proc=true;
	}
 
	int curr=l*2+1;
	int ans=1;
 
	rep(x,20,0){
		if (tkd[curr][x].fi!=-1 && tkd[curr][x].fi/2<=r){
			ans+=tkd[curr][x].se;
			curr=tkd[curr][x].fi;
		}
	}
 
	return ans;
}

Compilation message (stderr)

towers.cpp: In constructor 'node::node(long long int, long long int)':
towers.cpp:51:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   51 |   s=_s,e=_e,m=s+e>>1;
      |               ~^~

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