Submission #1104670

#	Time	Username	Problem	Language	Result	Execution time	Memory
1104670		alexander707070	Shortcut (IOI16_shortcut)	C++14	71 / 100	2070 ms	19384 KiB

shortcut

#include<bits/stdc++.h>
#define MAXN 100007
using namespace std;

const long long inf=1e15;

int n,len[MAXN],d[MAXN],c;
long long pos[MAXN];

int where[MAXN],cnt;
pair<long long,int> mp[MAXN];

struct rect{
	long long minx,maxx;
	long long miny,maxy;

	inline friend rect operator + (rect fr,rect sc){
		return {max(fr.minx,sc.minx),min(fr.maxx,sc.maxx),max(fr.miny,sc.miny),min(fr.maxy,sc.maxy)};
	}
};

struct ST{
	struct node{
		long long mins,maxs;
	};

	node tree[4*MAXN];

	void init(){
		for(int i=0;i<=4*n;i++){
			tree[i].mins=inf; tree[i].maxs=-inf;
		}
	}

	void update(int v,int l,int r,int pos,long long val){
		if(l==r){
			tree[v].mins=min(tree[v].mins,val);
			tree[v].maxs=max(tree[v].maxs,val);
		}else{
			int tt=(l+r)/2;

			if(pos<=tt){
				update(2*v,l,tt,pos,val);
			}else{
				update(2*v+1,tt+1,r,pos,val);
			}

			tree[v].mins=min(tree[2*v].mins,tree[2*v+1].mins);
			tree[v].maxs=max(tree[2*v].maxs,tree[2*v+1].maxs);
		}
	
	}
	pair<long long,long long> combine(pair<long long,long long> fr,pair<long long,long long> sc){
		return {min(fr.first,sc.first),max(fr.second,sc.second)};
	}

	pair<long long,long long> getinfo(int v,int l,int r,int ll,int rr){
		if(ll>rr)return {inf,-inf};

		if(l==ll and r==rr)return {tree[v].mins,tree[v].maxs};
		
		int tt=(l+r)/2;
		return combine( getinfo(2*v,l,tt,ll,min(tt,rr)) , getinfo(2*v+1,tt+1,r,max(tt+1,ll),rr) ); 
	}
}segx,segy;

int bin(long long x){
	int l=0,r=n+1,tt;

	while(l+1<r){
		tt=(l+r)/2;
		if(x<=mp[tt].first){
			r=tt;
		}else{
			l=tt;
		}
	}

	if(r==n+1)return cnt+1;
	return where[mp[r].second];
}

bool ok(long long fix){
	rect s={-inf,inf,-inf,inf},curr;

	segx.init(); segy.init();

	for(int i=n;i>=1;i--){

		int from=bin(fix+pos[i]-d[i]+1);

		pair<long long,long long> s1=segx.getinfo(1,1,cnt,from,cnt);
		pair<long long,long long> s2=segy.getinfo(1,1,cnt,from,cnt);

		curr={pos[i]+d[i]+s1.second-fix+c , pos[i]-d[i]+s2.first+fix-c , -pos[i]+d[i]+s1.second-fix+c , -pos[i]-d[i]+s2.first+fix-c};
		s=s+curr;

		segx.update(1,1,cnt,where[i],pos[i]+d[i]);
		segy.update(1,1,cnt,where[i],pos[i]-d[i]);
	}

	for(int i=1;i<=n;i++){
		int l=i+1,r=n+1,tt;

		while(l+1<r){
			tt=(l+r)/2;
			if(pos[tt]<=min(s.maxx-pos[i],s.maxy+pos[i])){
				l=tt;
			}else{
				r=tt;
			}
		}

		if(pos[l]-pos[i]>=s.miny and pos[l]-pos[i]<=s.maxy and pos[l]+pos[i]>=s.minx and pos[l]+pos[i]<=s.maxx)return true;
	}

	return false;
}

long long find_shortcut(int N,vector<int> L,vector<int> D, int C){
	n=N; c=C;

	for(int i=1;i<=n-1;i++){
		len[i]=L[i-1];
	}

	for(int i=2;i<=n;i++){
		pos[i]=pos[i-1]+len[i-1];
	}

	for(int i=1;i<=n;i++){
		d[i]=D[i-1];
	}

	for(int i=1;i<=n;i++)mp[i]={pos[i]+d[i],i};
	sort(mp+1,mp+n+1);

	for(int i=1;i<=n;i++){
		if(i==1 or mp[i].first!=mp[i-1].first)cnt++;
		where[mp[i].second]=cnt;
	}

	long long l=0,r=inf,tt;
	while(l+1<r){
		tt=(l+r)/2;
		if(ok(tt)){
			r=tt;
		}else{
			l=tt;
		}
	}

	return r;
}

/*int main(){

	//cout<<find_shortcut(9, {10, 10, 10, 10, 10, 10, 10, 10},{20, 0, 30, 0, 0, 40, 0, 40, 0}, 30)<<"\n";
	//cout<<find_shortcut(4, {2, 2, 2},{1, 10, 10, 1}, 1)<<"\n";
	//cout<<find_shortcut(3, {1, 1},{1, 1, 1}, 3)<<"\n";



	return 0;
}*/

• Subtask 1: 9 / 9
• Subtask 2: 14 / 14
• Subtask 3: 8 / 8
• Subtask 4: 7 / 7
• Subtask 5: 33 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3