Submission #928537

#	Time	Username	Problem	Language	Result	Execution time	Memory
928537		koukirocks	Maze (JOI23_ho_t3)	C++17	86 / 100	2076 ms	435484 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;
vector<set<int> > rw,col;
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;
}
 
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));
	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);
	col.resize(c);
	for (int i=0;i<r;i++) {
		for (int j=0;j<c;j++) {
			rw[i].insert(j);
			col[j].insert(i);
		}
	}
	deque<pii> DBFS;
	rw[s.first].erase(s.second);
	col[s.second].erase(s.first);
	dis[s.first][s.second]=0;
	DBFS.push_front(s);
	while (!DBFS.empty()) {
		auto [vx,vy]=DBFS.front();
//		cout<<vx<<" "<<vy<<" v\n"<<flush;
		DBFS.pop_front();
		for (int k=0;k<4;k++) {
			int nx=vx+dir[k][0];
			int ny=vy+dir[k][1];
//			cout<<nx<<" "<<ny<<" n\n";
//			if (in(nx,ny)) cout<<dis[nx][ny]<<" "<<dis[vx][vy]<<" "<<mp[nx][ny]<<"\n";
			if (in(nx,ny) and !mp[nx][ny] and dis[nx][ny]>dis[vx][vy]) {
				DBFS.push_front({nx,ny});
				dis[nx][ny]=dis[vx][vy];
				rw[nx].erase(ny);
				col[ny].erase(nx);
			}
		}
		if (inrg(vx,vy,g.first,g.second)) {
			if (dis[g.first][g.second]>dis[vx][vy]+1) {
				dis[g.first][g.second]=dis[vx][vy]+1;
				DBFS.push_back(g);
				rw[g.first].erase(g.second);
				col[g.second].erase(g.first);
			}
			continue;
		}
		if (vx-n>=0) {
			int nx=vx-n;
			auto it=rw[nx].upper_bound(max(0,vy-n+1)-1);
			while (it!=rw[nx].end() and *it<min(c,vy+n)) { // up
//				cout<<nx<<" "<<ny<<" nU\n";
				if (dis[nx][*it]>dis[vx][vy]+1) {
					DBFS.push_back({nx,*it});
					dis[nx][*it]=dis[vx][vy]+1;
				}
				it=rw[nx].erase(it);
			}
		}
		if (vx+n<r) {
			int nx=vx+n;
			auto it=rw[nx].upper_bound(max(0,vy-n+1)-1);
			while (it!=rw[nx].end() and *it<min(c,vy+n)) { // down
//				cout<<nx<<" "<<ny<<" nD\n";
				if (dis[nx][*it]>dis[vx][vy]+1) {
					DBFS.push_back({nx,*it});
					dis[nx][*it]=dis[vx][vy]+1;
				}
				it=rw[nx].erase(it);
			}
		}
		if (vy+n<c) {
			int ny=vy+n;
			auto it=col[ny].upper_bound(max(0,vx-n+1)-1);
			while (it!=col[ny].end() and *it<min(r,vx+n)) { // right
//				cout<<nx<<" "<<ny<<" nR\n";
				if (dis[*it][ny]>dis[vx][vy]+1) {
					DBFS.push_back({*it,ny});
					dis[*it][ny]=dis[vx][vy]+1;
				}
				it=col[ny].erase(it);
			}
		}
		if (vy-n>=0) {
			int ny=vy-n;
			auto it=col[ny].upper_bound(max(0,vx-n+1)-1);
			while (it!=col[ny].end() and *it<min(r,vx+n)) { // left
//				cout<<nx<<" "<<ny<<" nL\n";
				if (dis[*it][ny]>dis[vx][vy]+1) {
					DBFS.push_back({*it,ny});
					dis[*it][ny]=dis[vx][vy]+1;
				}
				it=col[ny].erase(it);
			}
		}
	}
//	for (int i=0;i<r;i++) {
//		for (int j=0;j<c;j++) cout<<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: 0 / 8
• Subtask 8: 0 / 6