Submission #466519

#	Time	Username	Problem	Language	Result	Execution time	Memory
466519		Valaki2	Awesome Arrowland Adventure (eJOI19_adventure)	C++14	100 / 100	139 ms	27232 KiB

adventure

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

#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<int, ll>
#define fi first
#define se second

void solve() {
    int n, m;
    cin >> n >> m;
    vector<vector<int> > board(1 + n + 1, vector<int> (1 + m + 1, -1));
    for(int i = 1; i <= n; ++i) {
        for(int j = 1; j <= m; ++j) {
            char ch;
            cin >> ch;
            if(ch == 'N') board[i][j] = 0;
            if(ch == 'E') board[i][j] = 3;
            if(ch == 'S') board[i][j] = 2;
            if(ch == 'W') board[i][j] = 1;
        }
    }
    vector<vector<vector<pair<int, pair<int, int> > > > > graph(1 + n + 1, vector<vector<pair<int, pair<int, int> > > > (1 + m + 1));
    for(int i = 1; i <= n; ++i) {
        for(int j = 1; j <= m; ++j) {
            // cout << i << " " << j << ":\n";
            if(board[i][j] == -1) continue;
            graph[i][j].pb(mp((board[i][j] + 0) % 4, mp(i - 1, j)));
            graph[i][j].pb(mp((board[i][j] + 1) % 4, mp(i, j + 1)));
            graph[i][j].pb(mp((board[i][j] + 2) % 4, mp(i + 1, j)));
            graph[i][j].pb(mp((board[i][j] + 3) % 4, mp(i, j - 1)));
            // for(auto p : graph[i][j]) cout << "{" << p.fi << " {" << p.se.fi << " " << p.se.se << "} }\n";
        }
    }
    vector<vector<bool> > done(1 + n + 1, vector<bool> (1 + m + 1, false));
    vector<vector<int> > dist(1 + n + 1, vector<int> (1 + m + 1, 0));
    priority_queue<pair<int, pair<int, int> > > q;
    q.push(mp(0, mp(1, 1)));
    while(!q.empty()) {
        auto cur = q.top();
        q.pop();
        int i = cur.se.fi;
        int j = cur.se.se;
        int d = -cur.fi;
        if(!done[i][j]) {
            done[i][j] = true;
            dist[i][j] = d;
            for(auto nei : graph[i][j]) {
                if(!done[nei.se.fi][nei.se.se]) {
                    q.push(mp(-(d + nei.fi), mp(nei.se.fi, nei.se.se)));
                }
            }
        }
    }
    if(!done[n][m]) cout << "-1\n";
    else cout << dist[n][m] << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}

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