Submission #968691

#	Time	Username	Problem	Language	Result	Execution time	Memory
968691		NintsiChkhaidze	Nautilus (BOI19_nautilus)	C++17	100 / 100	204 ms	157800 KiB

nautilus

#include <bits/stdc++.h>
#define ll long long
#define s second
#define f first
#define pb push_back
#define left (h*2),l,(l + r)/2
#define right (h*2+1),(l+r)/2 + 1,r
#define pii pair <int,int>
using namespace std;

const int N = 503;
char a[N][N];
vector <pii> neighbours = {{0,1}, {0,-1}, {1,0}, {-1,0}};
int n,m;
bitset <501> dp[N][5003];
bitset <501> mask[N];

bool valid(int x,int y){
	return (x >= 1 && x <= n && y >= 1 && y <= m && a[x][y] == '.');
}

signed main(){
	ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);

	int k;
	cin>>n>>m>>k;

	for (int i = 1; i <= n; i++)
		for (int j = 1; j <= m; j++){
			cin >> a[i][j];
			if (a[i][j] == '.') dp[i][0][j] = 1,mask[i][j] = 1;
			else mask[i][j] = 0;
		}

	string s;
	cin>>s;

	map <char,pii> mp;
	mp['N'] = {-1,0};
	mp['S'] = {1,0};
	mp['E'] = {0,+1};
	mp['W'] = {0,-1};

	s='%' + s;
	for (int i = 1; i <= k; i++){

		for (int x = 1; x <= n; x++){
			bitset <501> nw;
			if (s[i] == 'E' || s[i] == '?'){
				nw |= (dp[x][i - 1] << 1) & mask[x];
			}

			if (s[i] == 'W' || s[i] == '?'){
				nw |= (dp[x][i - 1] >> 1) & mask[x];
			}

			if (s[i] == 'N' || s[i] == '?'){
				nw |= dp[x + 1][i - 1] & mask[x];
			}

			if (s[i] == 'S' || s[i] == '?'){
				nw |= dp[x - 1][i - 1] & mask[x];
			}

			dp[x][i] = nw;
		}

	}

	int ans=0;
	for (int i = 1; i <= n; i++)
		ans += dp[i][k].count();
	cout<<ans;
}

• Subtask 1: 29 / 29
• Subtask 2: 37 / 37
• Subtask 3: 34 / 34