Submission #277556

#	Time	Username	Problem	Language	Result	Execution time	Memory
277556		JuliusMieliauskas	Awesome Arrowland Adventure (eJOI19_adventure)	C++14	100 / 100	132 ms	22000 KiB

adventure

#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()
#define vi vector<int>
#define vll vector<long long>
#define MOD 1000000007
#define endl '\n'

typedef long long ll;

void print(vi v){
    cout<<"Contents of vector:\n";
    for(auto x : v) cout<<x<<" ";
    cout<<endl<<endl;
}

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

vector<pair<int, int> > adj[509 * 509];

int m, n;
char ar[509][509];
int dists[509 * 509];

bool in(int i, int j){
    return (i >= 0) && (j >= 0) && (i<m) && (j<n);
}

void fillAdj(){
    for(int i = 0; i<m; i++){
        for(int j = 0; j<n; j++){
            if(ar[i][j] == 'E'){
                for(int k = 0; k<4; k++){
                    int ci = i + dy[k], cj = j + dx[k];

                    if(in(ci, cj)){
                        if(k == 0) { /// Going W
                            adj[i*n + j].push_back({ci*n + cj, 2});
                        }
                        if(k == 1) { /// Going N
                            adj[i*n + j].push_back({ci*n + cj, 3});
                        }
                        if(k == 2) { /// Going E
                            adj[i*n + j].push_back({ci*n + cj, 0});
                        }
                        if(k == 3) { /// Going S
                            adj[i*n + j].push_back({ci*n + cj, 1});
                        }
                    }
                }
            }
            if(ar[i][j] == 'W'){
                for(int k = 0; k<4; k++){
                    int ci = i + dy[k], cj = j + dx[k];

                    if(in(ci, cj)){
                        if(k == 0) { /// Going W
                            adj[i*n + j].push_back({ci*n + cj, 0});
                        }
                        if(k == 1) { /// Going N
                            adj[i*n + j].push_back({ci*n + cj, 1});
                        }
                        if(k == 2) { /// Going E
                            adj[i*n + j].push_back({ci*n + cj, 2});
                        }
                        if(k == 3) { /// Going S
                            adj[i*n + j].push_back({ci*n + cj, 3});
                        }
                    }
                }
            }
            if(ar[i][j] == 'S'){
                for(int k = 0; k<4; k++){
                    int ci = i + dy[k], cj = j + dx[k];

                    if(in(ci, cj)){
                        if(k == 0) { /// Going W
                            adj[i*n + j].push_back({ci*n + cj, 1});
                        }
                        if(k == 1) { /// Going N
                            adj[i*n + j].push_back({ci*n + cj, 2});
                        }
                        if(k == 2) { /// Going E
                            adj[i*n + j].push_back({ci*n + cj, 3});
                        }
                        if(k == 3) { /// Going S
                            adj[i*n + j].push_back({ci*n + cj, 0});
                        }
                    }
                }
            }
            if(ar[i][j] == 'N'){
                for(int k = 0; k<4; k++){
                    int ci = i + dy[k], cj = j + dx[k];

                    if(in(ci, cj)){
                        if(k == 0) { /// Going W
                            adj[i*n + j].push_back({ci*n + cj, 3});
                        }
                        if(k == 1) { /// Going N
                            adj[i*n + j].push_back({ci*n + cj, 0});
                        }
                        if(k == 2) { /// Going E
                            adj[i*n + j].push_back({ci*n + cj, 1});
                        }
                        if(k == 3) { /// Going S
                            adj[i*n + j].push_back({ci*n + cj, 2});
                        }
                    }
                }
            }
        }
    }
}

void dijkstra(int source){
    bool visited[n*m];
    for(int i = 0; i<m; i++){
        for(int j = 0; j<n; j++) dists[i*n + j] = INT_MAX;
    }
    for(int i = 0; i<m; i++) for(int j = 0; j<n; j++) visited[i*n + j] = false;
    priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > pq;
    pq.push({0, source});
    dists[source] = 0;
    while (!pq.empty()) {
        int u = pq.top().second; pq.pop();

        if (visited[u]) continue;
        else visited[u] = true;
        //cout<<"From "<<u<<":"<<endl;
        for(auto v : adj[u]) {
            //cout<<v.first<<endl;
            if (dists[v.first] > dists[u] + v.second) {
                dists[v.first] = dists[u] + v.second;
                pq.push({dists[v.first], v.first});
            }
        }
        //cout<<endl;
    }
}

void solve(){
    cin>>m>>n;
    for(int i = 0; i<m; i++) for(int j = 0; j<n; j++) cin>>ar[i][j];
    fillAdj();
    dijkstra(0);

    /*for(int i = 0; i<m; i++){
        for(int j = 0; j<n; j++){
            cout<<dists[i*n + j]<<" ";
        }
        cout<<endl;
    }*/

    if(dists[m*n - 1] == INT_MAX) cout<<"-1"<<endl;
    else cout<<dists[m*n - 1]<<endl;
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    //ifstream cin(""); ofstream cout("");///cia failai

    //int T; cin>>T;
    int T = 1;

    for(int it = 1; it<=T; it++){
        solve();

    }
}

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