Submission #1183427

#	Time	Username	Problem	Language	Result	Execution time	Memory
1183427		nagorn_ph	Awesome Arrowland Adventure (eJOI19_adventure)	C++20	100 / 100	66 ms	10680 KiB

adventure

#include <bits/stdc++.h>
#define int long long
#define double long double
#define pii pair <int,int>
#define tiii tuple <int, int, int>
#define f first
#define s second
#define all(x) x.begin(), x.end()
#define ub(a, b) upper_bound(a.begin(), a.end(), b) - a.begin()
#define lb(a, b) lower_bound(a.begin(), a.end(), b) - a.begin()
#define ve vector
#define graph(a, n) vector <int> a[n];
#define wgraph(a, n) vector <pii> a[n];
#define emb emplace_back
#define em emplace
#define ins insert
#define er erase
#define iShowSpeed cin.tie(NULL)->sync_with_stdio(false)

using namespace std;

template <typename T>
using greater_priority_queue = priority_queue<T, vector<T>, greater<T>>;

const int mod = 1e9 + 7;
const int inf = 1e18;

int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};

int n, m; 

bool inside(int x, int y) {
    return x > 0 && x <= n && y > 0 && y <= m;
}

int dir(char c) {
    if (c == 'E') return 0;
    if (c == 'S') return 1;
    if (c == 'W') return 2;
    if (c == 'N') return 3;
    if (c == 'X') return -1;
}

int32_t main(){
    iShowSpeed;
    cin >> n >> m;
    vector <vector <int>> a(n + 1, vector <int> (m + 1));
    for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) {
        char c; cin >> c;
        a[i][j] = dir(c);
    }
    vector <vector <int>> dis(n + 1, vector <int> (m + 1, inf)); dis[1][1] = 0;
    greater_priority_queue <tiii> q; q.emplace(0, 1, 1);
    while (!q.empty()) {
        auto [w, x, y] = q.top(); q.pop();
        // cout << x << ", " << y << ": " << w << "\n";
        if (w > dis[x][y] || a[x][y] == -1) continue;
        for (int i = 0; i < 4; i++) {
            int nx = x + dx[(a[x][y] + i) % 4], ny = y + dy[(a[x][y] + i) % 4];
            if (!inside(nx, ny) || dis[nx][ny] <= dis[x][y] + i) continue;
            dis[nx][ny] = dis[x][y] + i;
            q.emplace(dis[nx][ny], nx, ny);
        }
    }
    cout << (dis[n][m] == inf ? -1 : dis[n][m]);
}

Compilation message (stderr)

adventure.cpp: In function 'long long int dir(char)':
adventure.cpp:43:1: warning: control reaches end of non-void function [-Wreturn-type]
   43 | }
      | ^

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