Submission #845862

#	Time	Username	Problem	Language	Result	Execution time	Memory
845862		konber	Awesome Arrowland Adventure (eJOI19_adventure)	C++14	100 / 100	107 ms	27304 KiB

adventure

#include <iostream>
#include <vector>
#include <cstring>
#include <queue>

using namespace std;
typedef pair<int,int> pi;

vector<pair<int, pi>> g[502][502];
int N, M;

int dijkstra(){
    int d[M][N], z[M][N];
    for(int i=0; i < M; i++) for(int j=0; j < N; j++){
        d[i][j] = 1e9;
        z[i][j] = 0;
    }

    d[0][0] = 0;
    priority_queue<pair<int, pi>> pq;
    pq.push(make_pair(0, make_pair(0, 0)));
    while(!pq.empty()){
        int i=pq.top().second.first;
        int j=pq.top().second.second;
        pq.pop();

        if(z[i][j]) continue;
        z[i][j] = 1;
        for(auto u: g[i][j]){
            if(d[u.second.first][u.second.second] > d[i][j] + u.first){
                d[u.second.first][u.second.second] = d[i][j] + u.first;
                pq.push(make_pair(-d[u.second.first][u.second.second], make_pair(u.second.first, u.second.second)));
            }
        }
    }
    return d[M-1][N-1];
}

int main()
{
    scanf("%d%d", &M, &N);
    for(int i=0; i < M; i++){
        for(int j=0; j < N; j++){
            char o;
            scanf(" %c", &o);
            if(o=='E'){
                if(j < N-1) g[i][j].push_back(make_pair(0, make_pair(i, j+1)));
                if(i < M-1) g[i][j].push_back(make_pair(1, make_pair(i+1, j)));
                if(j) g[i][j].push_back(make_pair(2, make_pair(i, j-1)));
                if(i) g[i][j].push_back(make_pair(3, make_pair(i-1, j)));
            }
            else if(o=='N'){
                if(j < N-1) g[i][j].push_back(make_pair(1, make_pair(i, j+1)));
                if(i < M-1) g[i][j].push_back(make_pair(2, make_pair(i+1, j)));
                if(j) g[i][j].push_back(make_pair(3, make_pair(i, j-1)));
                if(i) g[i][j].push_back(make_pair(0, make_pair(i-1, j)));
            }
            else if(o=='W'){
                if(j < N-1) g[i][j].push_back(make_pair(2, make_pair(i, j+1)));
                if(i < M-1) g[i][j].push_back(make_pair(3, make_pair(i+1, j)));
                if(j) g[i][j].push_back(make_pair(0, make_pair(i, j-1)));
                if(i) g[i][j].push_back(make_pair(1, make_pair(i-1, j)));
            }
            else if(o=='S'){
                if(j < N-1) g[i][j].push_back(make_pair(3, make_pair(i, j+1)));
                if(i < M-1) g[i][j].push_back(make_pair(0, make_pair(i+1, j)));
                if(j) g[i][j].push_back(make_pair(1, make_pair(i, j-1)));
                if(i) g[i][j].push_back(make_pair(2, make_pair(i-1, j)));
            }
        }
    }
    int ans=dijkstra();
    if(ans==1e9) printf("-1\n");
    else
        printf("%d\n", ans);
}

Compilation message (stderr)

adventure.cpp: In function 'int main()':
adventure.cpp:41:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |     scanf("%d%d", &M, &N);
      |     ~~~~~^~~~~~~~~~~~~~~~
adventure.cpp:45:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |             scanf(" %c", &o);
      |             ~~~~~^~~~~~~~~~~

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