Submission #553444

#	Time	Username	Problem	Language	Result	Execution time	Memory
553444		new_acc	Portals (BOI14_portals)	C++14	70 / 100	1087 ms	45892 KiB

portals

#include<bits/stdc++.h>
#define fi first
#define se second
#define pitem item*
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<ll> vl;
const int N=1e3+10;
const int SS=1<<19;
const int INFi=2e9;
const ll INFl=1e13;
const ll mod2=998244353;
const ll mod=1e9+7;
const ll mod3=1000696969;
const ll p=70032301;
const ull p2=913;
const int L=20;
int last[N][N][4],odl[N][N],m,n,naj[N][N];
char t[N][N];
priority_queue<pair<int,pair<int,int> >, vector<pair<int,pair<int,int> > >,greater<pair<int,pair<int,int> > > >deq;
bool vis[N][N];
bool inn(int a,int b){
	return (a>=1 and a<=n and b>=1 and b<=m and t[a][b]!='#');
}
void add(int a,int b){
	vis[a][b]=1;
	if(inn(a-1,b) and !vis[a-1][b]) deq.push({odl[a][b]+1,{a-1,b}});
	if(inn(a+1,b) and !vis[a+1][b]) deq.push({odl[a][b]+1,{a+1,b}});
	if(inn(a,b+1) and !vis[a][b+1]) deq.push({odl[a][b]+1,{a,b+1}});
	if(inn(a,b-1) and !vis[a][b-1]) deq.push({odl[a][b]+1,{a,b-1}});
	if(!vis[a][last[a][b][0]]) deq.push({odl[a][b]+naj[a][b]+1,{a,last[a][b][0]}});
	if(!vis[a][last[a][b][1]]) deq.push({odl[a][b]+naj[a][b]+1,{a,last[a][b][1]}});
	if(!vis[last[a][b][2]][b]) deq.push({odl[a][b]+naj[a][b]+1,{last[a][b][2],b}});
	if(!vis[last[a][b][3]][b]) deq.push({odl[a][b]+naj[a][b]+1,{last[a][b][3],b}});
}
void solve(){
	cin>>n>>m;
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++) cin>>t[i][j];
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			if(t[i][j-1]=='#' or j==1) last[i][j][0]=j;
			else last[i][j][0]=last[i][j-1][0];
		}	
	}
	for(int i=1;i<=n;i++){
		for(int j=m;j>=1;j--){
			if(t[i][j+1]=='#' or j==m) last[i][j][1]=j;
			else last[i][j][1]=last[i][j+1][1];
		}
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			if(t[i-1][j]=='#' or i==1) last[i][j][2]=i;
			else last[i][j][2]=last[i-1][j][2];
		}
	}
	for(int i=n;i>=1;i--){
		for(int j=1;j<=m;j++){
			if(t[i+1][j]=='#' or i==n) last[i][j][3]=i;
			else last[i][j][3]=last[i+1][j][3];
		}
	}
	for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) naj[i][j]=min({j-last[i][j][0],last[i][j][1]-j,i-last[i][j][2],last[i][j][3]-i});
	for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) deq.push({naj[i][j],{i,j}});
	while(deq.size()){
		pair<int,pair<int,int> >v=deq.top();
		deq.pop();
		if(vis[v.se.fi][v.se.se]) continue;
		naj[v.se.fi][v.se.se]=v.fi;
		vis[v.se.fi][v.se.se]=1;
		pair<int,int>u=v.se;
		if(inn(u.fi+1,u.se) and !vis[u.fi+1][u.se]) deq.push({naj[u.fi][u.se]+1,{u.fi+1,u.se}});
		if(inn(u.fi-1,u.se) and !vis[u.fi-1][u.se]) deq.push({naj[u.fi][u.se]+1,{u.fi-1,u.se}});
		if(inn(u.fi,u.se+1) and !vis[u.fi][u.se+1]) deq.push({naj[u.fi][u.se]+1,{u.fi,u.se+1}});
		if(inn(u.fi,u.se-1) and !vis[u.fi][u.se-1]) deq.push({naj[u.fi][u.se]+1,{u.fi,u.se-1}});
	}
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++) vis[i][j]=0;
	pair<int,int>s,tt;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
		 	if(t[i][j]=='S') s={i,j};
		 	if(t[i][j]=='C') tt={i,j};
		}
	}
	deq.push({0,s});
	while(deq.size()){
		pair<int,pair<int,int> >v=deq.top();
		deq.pop();
		if(vis[v.se.fi][v.se.se]) continue;
		odl[v.se.fi][v.se.se]=v.fi;
		add(v.se.fi,v.se.se);
	}
	cout<<odl[tt.fi][tt.se]<<"\n";
}
int main(){
	ios_base::sync_with_stdio(0),cin.tie(0);
	solve();
}

• Subtask 1: 11 / 11
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 19 / 19
• Subtask 5: 0 / 30