Submission #976300

#	Time	Username	Problem	Language	Result	Execution time	Memory
976300		vjudge1	Awesome Arrowland Adventure (eJOI19_adventure)	C++17	100 / 100	71 ms	9424 KiB

adventure

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define lld double
#define int ll
#define usaco(fname) freopen(#fname ".in","r",stdin);freopen(#fname ".out","w",stdout);
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
// const ll INF = 1e18;
const int INF = 1e18;
const int mod = 1e9+7;
const lld PI = acos(-1.0);
#define debug(x) cout << #x << ": " << x << endl;
#define add(a, b) a += b, a %= mod
#define mul(a, b) ((a % mod) * (b % mod)) % mod
#define all(x) x.begin(),x.end()

int tr(char x) {
  if (x == 'N') x = 'a';
  else if ( x== 'E') x = 'b';
  else if (x == 'S') x = 'c';
  else x = 'd';
  return x;
}

// get dist
int dist(char a, char b) {
  int x = tr(a), y = tr(b);
  int ans = (y-x)%4;
  ans += 4;
  ans %= 4;
  return ans;
}

int di[] = {1, -1, 0, 0, 1, 1, -1, -1};
int dj[] = {0, 0, 1, -1, 1, -1, 1, -1};
char mapping[] = {'S', 'N', 'E', 'W'};
#define info tuple<int, int, int>

void solve() {
  int n,m;cin>>n>>m;
  vector<string> grid(n);
  for (int i = 0; i < n; i++) cin >> grid[i];

  // cost i j
  priority_queue<info, vector<info>, greater<info>> pq;
  pq.push({0, 0, 0});

  vector<vector<int>> dp(n, vector<int>(m, INF));
  while (!pq.empty()) {
    auto [cost, i, j] = pq.top();pq.pop();
    dp[i][j] = min(dp[i][j], cost);
    if (grid[i][j] == 'X' || cost > dp[i][j]) continue;

    // cout << i << " " << j << endl;

    for (int k = 0; k < 4; k++) {
      int nexti = i + di[k], nextj = j + dj[k];
      char dir = mapping[k];

      int dis = dist(grid[i][j], dir);
      if (nexti >= 0 && nexti < n && nextj >= 0 && nextj < m && cost+dis < dp[nexti][nextj]) {
        dp[nexti][nextj] = cost+dis;
        pq.push({cost + dis, nexti, nextj});
      }
    }
  }

  cout << (dp[n-1][m-1] == INF ? -1 : dp[n-1][m-1]) << endl;
}

int32_t main() {
  ios_base::sync_with_stdio(0);cin.tie(0);
  int t=1;
  while(t--) solve();

  return 0;
}

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