Submission #787053

#	Time	Username	Problem	Language	Result	Execution time	Memory
787053		Bula	Awesome Arrowland Adventure (eJOI19_adventure)	C++14	100 / 100	93 ms	28100 KiB

adventure

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

#define ll long long
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int ll
const ll mod=1e9+7;
int n,m;
char c[501][501];

bool check(int x, int y){
	if(x<1 || y<1 || x>n || y>m ) return false;
	if(x==n && y==m) return true;
	if(c[x][y]=='X') return false;
	return true;
}

main(){
	cin>>n>>m;
	vector< pair<int,int> > v[n*m+1];
	
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			cin>>c[i][j];
		}
	}
	vector<pair<int,int> > p={{-1,0},{0,1},{1,0},{0,-1}};
	vector<int> t={-m,1,m,-1};
	map<char,int> mp;
	mp['N']=0;
	mp['E']=1;
	mp['S']=2;
	mp['W']=3;
	int x=0;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			x++;
			if(c[i][j]=='X') continue;
			int l=mp[c[i][j]];
			for(int k=0;k<4;k++){
				int a=i+p[k].first;
				int b=j+p[k].second;
				bool ok = check(a,b);
				if(ok==false) continue;
				int dist;
				if(k<l) dist=(k+4)-l;
				else dist=k-l;
				v[x].pb({x+t[k],dist});
			}
		}
	}
//	for(int i=1;i<=n*m;i++){
//		for(int j=0;j<v[i].size();j++){
//			cout<<i<<" "<<v[i][j].first<<" "<<v[i][j].second<<endl;
//		}
//	}
	vector<int> d(n*m+1,INT_MAX);
	d[1]=0;
	set< pair<int,int> > q;
	q.insert({0,1});
	while(!q.empty()){
		//pair<int,int> pr=q.begin();
		int u=q.begin()->second;
		q.erase(q.begin());
		
		for(auto edge : v[u]){
			int to = edge.first;
			int len = edge.second;
		
			if(d[u] + len < d[to]){
				q.erase({d[to],to});
				d[to]=d[u]+len;
				q.insert({d[to],to});
			}
		}
	}
//	for(int i=1;i<=n*m;i++) cout<<i<<" "<<d[i]<<endl;
	if(d[n*m] == INT_MAX) cout<<-1<<endl;
	else cout<<d[n*m]<<endl;
}

Compilation message (stderr)

adventure.cpp:20:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   20 | main(){
      | ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 12 / 12
• Subtask 4: 16 / 16
• Subtask 5: 50 / 50