Submission #791637

#	Time	Username	Problem	Language	Result	Execution time	Memory
791637		otarius	Awesome Arrowland Adventure (eJOI19_adventure)	C++17	100 / 100	62 ms	2136 KiB

adventure

#include <iostream>
#include <algorithm>
#include <vector>
#include <set>
#include <cstring>
#include <queue>
#include <map>
#include <cmath>
#include <iomanip>
using namespace std;

#define ff first
#define sc second
#define pb push_back
#define ll long long
#define pll pair<ll, ll>
#define pii pair <int, int>
#define ull unsigned long long

// #define int long long
// #define int unsigned long long

const ll inf = 1e9 + 7;
const ll weirdMod = 998244353;

int dx[] = {-1, 0, 1, 0};
int dy[] = {0, 1, 0, -1};
char dir[] = {'N', 'E', 'S', 'W', 'N', 'E', 'S', 'W'};

char arr[505][505];
int n, m, d[505][505], x, y, a, b;
int get(char v, char u) {
    int pos;
    for (int i = 0; i < 4; i++)
        if (dir[i] == v) pos = i;
    int ans = 0;
    for ( ; pos < 8; pos++) {
        if (dir[pos] == u) break;
        else ans++;
    } return ans;
}
void dijkstra() {
    d[1][1] = 0;
    set<pair<int, pii>> st;
    st.insert({0, {1, 1}});
    pair<int, pii> cur;
    int num = 0;
    while (!st.empty()) {
        cur = *st.begin();
        st.erase(st.begin());
        x = cur.sc.ff; y = cur.sc.sc;
        if (arr[x][y] == 'X') continue;
        for (int i = 0; i < 4; i++) {
            a = x + dx[i];
            b = y + dy[i];
            if (a > 0 && b > 0 && a <= n && b <= m) {
                if (d[a][b] > d[x][y] + get(arr[x][y], dir[i])) {
                    st.erase({d[a][b], {a, b}});
                    d[a][b] = d[x][y] + get(arr[x][y], dir[i]);
                    st.insert({d[a][b], {a, b}});
                }
            }
        }
    } if (d[n][m] == inf)
        cout << -1;
    else cout << d[n][m];
}
void solve() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> arr[i][j]; d[i][j] = inf;
        }
    } if (n == 1 && m == 1) {
        cout << 0; return;
    } if (arr[1][1] == 'X') {
        cout << -1; return;
    } dijkstra();
}
int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
        cout << '\n';
    } return 0;
}

Compilation message (stderr)

adventure.cpp: In function 'void dijkstra()':
adventure.cpp:47:9: warning: unused variable 'num' [-Wunused-variable]
   47 |     int num = 0;
      |         ^~~
adventure.cpp: In function 'int get(char, char)':
adventure.cpp:33:9: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized]
   33 |     int pos;
      |         ^~~
adventure.cpp: In function 'void dijkstra()':
adventure.cpp:33:9: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized]
adventure.cpp:33:9: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized]

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