Submission #969794

#	Time	Username	Problem	Language	Result	Execution time	Memory
969794		pcc	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	205 ms	183348 KiB

skyscraper

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

#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>


const int inf = 1e9;
const int mxn = 3e4+10;
const int mxe = mxn*sqrt(mxn)*2;
const int mxv = mxe;

map<pii,vector<int>> mp;
int N,M;
int ecnt,vcnt;
int to[mxe],nid[mxe],wei[mxe];
int head[mxv];
int dist[mxv];
int S,T;

void add_edge(int a,int b,int w){
	ecnt++;
	nid[ecnt] = head[a];
	to[ecnt] = b;
	wei[ecnt] = w;
	head[a] = ecnt;
}

deque<pii> dq;
void BFS(){
	fill(dist,dist+mxv,inf);
	dist[S] = 0;
	dq.push_back(pii(0,S));
	while(!dq.empty()){
		auto [d,now] = dq.front();
		dq.pop_front();
		if(d != dist[now])continue;
		for(int eid = head[now];eid;eid = nid[eid]){
			int nxt = to[eid],w = wei[eid];
			//cout<<now<<' '<<nxt<<":"<<dist[now]+w<<' '<<dist[nxt]<<endl;
			if(!w){
				if(dist[nxt]>dist[now]){
					dist[nxt] = dist[now];
					dq.push_front(pii(dist[nxt],nxt));
				}
			}
			else{
				if(dist[nxt]>dist[now]+w){
					dist[nxt] = dist[now]+w;
					dq.push_back(pii(dist[nxt],nxt));
				}
			}
		}
	}
	return;
}


int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>N>>M;
	for(int i = 0;i<M;i++){
		pii tmp;
		cin>>tmp.fs>>tmp.sc;
		mp[pii(tmp.sc,tmp.fs%tmp.sc)].push_back(tmp.fs);
		if(!i)S = tmp.fs;
		if(i == 1)T = tmp.fs;
	}
	vcnt = N-1;
	for(auto &i:mp){
		sort(i.sc.rbegin(),i.sc.rend());
		for(int j = i.fs.sc;j<N;j+=i.fs.fs){
			vcnt++;
			add_edge(vcnt,j,0);
			while(!i.sc.empty()&&i.sc.back() == j){
				add_edge(i.sc.back(),vcnt,0);
				i.sc.pop_back();
			}
			if(j != i.fs.sc){
				add_edge(vcnt-1,vcnt,1);
				add_edge(vcnt,vcnt-1,1);
			}
		}
	}
	BFS();
	cout<<(dist[T]>=inf?-1:dist[T])<<'\n';
	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 0 / 43