Submission #976459

#	Time	Username	Problem	Language	Result	Execution time	Memory
976459		vjudge1	Awesome Arrowland Adventure (eJOI19_adventure)	C++17	50 / 100	2055 ms	75036 KiB

adventure

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define v(a) vector<a>
#define p(a, b) pair<a, b>
#define F first 
#define S second
ll n, m; 
map<p(ll, ll), bool> vis;
map<char, ll> base;
v(v(char)) arr;
bool pos(ll x, ll y){
    if(x < 0 || y < 0 || x >= n || y >= m) return false;
    if(vis[{x, y}]) return false;
    if(arr[x][y] == 'X' && x != n-1 && y != m-1) return false;
    return true;
}

ll cost(ll a, ll b){
    return ((b-a)+4)%4;
}
int main(){
    cin >> n >> m;
    arr.resize(n);
    for(int i = 0; i < n; i++)arr[i].resize(m);
    for(int i = 0; i < n; i++){
        for(int j = 0; j < m; j++) cin >> arr[i][j];
    }

    bool ok = false;
    queue<p(ll, ll)> temp;
    temp.push({0, 0});
    while(!temp.empty()){
        ll x = temp.front().F, y = temp.front().S;
        temp.pop();
        vis[{x, y}] = true;
        if(x == n-1 && y == m-1){
            ok = true;
            break;
        }    
        if(arr[x][y] == 'X') continue;
        if(pos(x+1, y))temp.push({x+1, y});
        if(pos(x, y+1)) temp.push({x, y+1});
        if(pos(x-1, y)) temp.push({x-1, y});
        if(pos(x, y-1)) temp.push({x, y-1});
    }

    if(!ok) cout << -1;
    else {
        vis.clear();
        priority_queue<p(ll, p(ll, ll)), v(p(ll, p(ll, ll))), greater<p(ll, p(ll, ll))> > pq;
        pq.push({0, {0, 0}});
        base['N'] = 1;
        base['E'] = 2;
        base['S'] = 3;
        base['W'] = 4;

        ll ans = 1e9;
        while(!pq.empty()){
            ll cur = pq.top().F, x = pq.top().S.F, y = pq.top().S.S;
            // cout << cur << " " << x << " " << y << endl;
            pq.pop();
            if(vis[{x, y}]) continue;
            vis[{x, y}] = true;
            if(x == n-1 && y == m-1){
                ans = cur;
                break;
            }

            if(arr[x][y] == 'X') continue;

            if(pos(x+1, y)) pq.push({cur + cost(base[arr[x][y]], 3), {x+1, y}});
            if(pos(x-1, y)) pq.push({cur + cost(base[arr[x][y]], 1), {x-1, y}});
            if(pos(x, y+1)) pq.push({cur + cost(base[arr[x][y]], 2), {x, y+1}});
            if(pos(x, y-1)) pq.push({cur + cost(base[arr[x][y]], 4), {x, y-1}});
        }

        cout << ans;
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 12 / 12
• Subtask 4: 16 / 16
• Subtask 5: 0 / 50