Submission #930056

#	Time	Username	Problem	Language	Result	Execution time	Memory
930056		koukirocks	Maze (JOI23_ho_t3)	C++17	100 / 100	798 ms	123044 KiB

Main

#include <bits/stdc++.h>
#define speed ios_base::sync_with_stdio(0); cin.tie(0)
#define all(x) (x).begin(),(x).end()
 
using namespace std;
typedef long long ll;
typedef long double ldb;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
 
const ll MAX=5e5+10,P=1e9+7;
const ll INF=0x3f3f3f3f,oo=0x3f3f3f3f3f3f3f3f;
 
const int dir[4][2]={{0,1},{1,0},{-1,0},{0,-1}};
int r,c,n;
pii s,g;
vector<vector<bool> > mp,vis;
vector<vector<int> > dis;

bool in(int x,int y) {
	return x>=0 and x<r and y>=0 and y<c;
}
 
bool inrg(int vx,int vy,int tgx,int tgy) {
	int dx=abs(tgx-vx);
	int dy=abs(tgy-vy);
	if (max(dx,dy)<=n and !(dx==n and dy==n)) return true;
	return false;
}

vector<vector<int> > rw;

int rwnxt(int i,int j) {
	if (j==c or !vis[i][j]) return j;
	return rw[i][j]=rwnxt(i,rw[i][j]);
}

vector<vector<int> > col;

int colnxt(int i,int j) {
	if (i==r or !vis[i][j]) return i;
	return col[i][j]=colnxt(col[i][j],j);
}

int main() {
	speed;
	cin>>r>>c>>n;
	cin>>s.first>>s.second;
	s.first--;s.second--;
	cin>>g.first>>g.second;
	g.first--;g.second--;
	mp.resize(r,vector<bool>(c));
	dis.resize(r,vector<int>(c,INF));
	vis.resize(r,vector<bool>(c,0));
	for (int i=0;i<r;i++) {
		for (int j=0;j<c;j++) {
			char c;
			cin>>c;
			if (c=='.') mp[i][j]=0;
			else mp[i][j]=1;
		}
	}
	rw.resize(r,vector<int>(c));
	col.resize(r,vector<int>(c));
	for (int i=0;i<r;i++) {
		for (int j=0;j<c;j++) {
			rw[i][j]=j+1;
			col[i][j]=i+1;
		}
	}
	vector<pii> cur0,cur1;
	cur0.emplace_back(s);
	vis[s.first][s.second]=true;
	dis[s.first][s.second]=0;
	while (!cur0.empty()) {
		while (!cur0.empty()) {
			auto [vx,vy]=cur0.back();
			cur1.emplace_back(vx,vy);
			cur0.pop_back();
			for (int k=0;k<4;k++) {
				int nx=vx+dir[k][0];
				int ny=vy+dir[k][1];
				if (in(nx,ny) and !mp[nx][ny] and !vis[nx][ny]) {
					dis[nx][ny]=dis[vx][vy];
					vis[nx][ny]=true;
					cur0.emplace_back(nx,ny);
//					cout<<nx<<" "<<ny<<"\n";
					if (vis[g.first][g.second]) goto found;
				}
			}
		}
		while (!cur1.empty()) {
			auto [vx,vy]=cur1.back();
			cur1.pop_back();
//			cout<<vx<<" "<<vy<<"\n"<<flush;
			if (inrg(vx,vy,g.first,g.second)) {
				dis[g.first][g.second]=dis[vx][vy]+1;
				goto found;
			}
			for (int nx:{max(0,vx-n),min(r-1,vx+n)}) {
//				cout<<nx<<" "<<max(0,vy-n+1)<<" rw\n"<<flush;
				int ny=rwnxt(nx,max(0,vy-n+1));
				while(ny<min(c,vy+n)) {
//					cout<<nx<<" "<<ny<<" rwn\n"<<flush;
					dis[nx][ny]=dis[vx][vy]+1;
					vis[nx][ny]=true;
					cur0.emplace_back(nx,ny);
					ny=rwnxt(nx,ny);
				}
			}
			for (int ny:{max(0,vy-n),min(c-1,vy+n)}) {
				int nx=colnxt(max(0,vx-n+1),ny);
				while(nx<min(r,vx+n)) {
//					cout<<nx<<" "<<ny<<" coln\n";
					dis[nx][ny]=dis[vx][vy]+1;
					vis[nx][ny]=true;
					cur0.emplace_back(nx,ny);
					nx=colnxt(nx,ny);
				}
			}
		}
//		cout<<"---------\n";
	}
	found:
//		for (int i=0;i<r;i++) {
//			for (int j=0;j<c;j++) cout<<(dis[i][j]==INF?0:dis[i][j])<<" ";
//			cout<<"\n";
//		}
	cout<<dis[g.first][g.second]<<"\n";
	return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 16 / 16
• Subtask 4: 19 / 19
• Subtask 5: 5 / 5
• Subtask 6: 19 / 19
• Subtask 7: 8 / 8
• Subtask 8: 6 / 6