Submission #464443

#	Time	Username	Problem	Language	Result	Execution time	Memory
464443		Sench2006	Awesome Arrowland Adventure (eJOI19_adventure)	C++14	100 / 100	83 ms	1584 KiB

adventure

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

#define ll long long
#define ar array

#define f first
#define s second
#define mpr make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

#define FOR(i, a, b) for(auto i = a; i < b; i++)
#define FORD(i, a, b) for(auto i = a - 1; i >= b; i--)
#define trav(x, v) for(auto x : v)

#define fastio ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define fileio freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);

// --------------- SOLUTION --------------- //

const int INF = 1e9;
int n, m;
char a[501][501];
int d[501][501];
set <pair<int, pair<int, int>>> s;

char dir[4] = {'W', 'S', 'E', 'N'};

bool valid(int x, int y) {
    return (x >= 0 && x < n && y >= 0 && y < m);
}

void read() {
    cin >> n >> m;
    FOR(i, 0, n) {
        FOR(j, 0, m) {
            cin >> a[i][j];
        }
    }
}

void make_inf() {
    FOR(i, 0, n) {
        FOR(j, 0, m) {
            d[i][j] = INF; 
        }
    }
}

void djk() {
    d[0][0] = 0;
    s.insert({0, {0, 0}});
    while (!s.empty()) {
        auto it = s.begin();
        int dist = (*it).f;
        int x = (*it).s.f;
        int y = (*it).s.s;
        s.erase(it);
        if (a[x][y] == 'X') {
            continue;
        }
        FOR(i, 0, 4) {
            int cnt = 0;
            int xx = 0, yy = 0;
            if (a[x][y] == dir[i]) cnt = 0;
            else if (a[x][y] == dir[(i + 1) % 4]) cnt = 1;
            else if (a[x][y] == dir[(i + 2) % 4]) cnt = 2;
            else cnt = 3;
            if (dir[i] == 'W') xx = 0, yy = -1;
            else if (dir[i] == 'S') xx = 1, yy = 0;
            else if (dir[i] == 'E') xx = 0, yy = 1;
            else xx = -1, yy = 0;
            if (valid(x + xx, y + yy) && d[x + xx][y + yy] > dist + cnt) {
                s.erase({d[x + xx][y + yy], {x + xx, y + yy}});
                d[x + xx][y + yy] = dist + cnt;
                s.insert({d[x + xx][y + yy], {x + xx, y + yy}});
            }
        }
    }
}

void display() {
    if(d[n - 1][m - 1] != INF)
        cout << d[n - 1][m - 1] << endl;
    else 
        cout << -1 << endl;
}

void solve() {
    read();
    make_inf();
    djk();
    display();
}

int main() {
    fastio;
    //fileio;
    int tests = 1;
    // cin >> tests;
    while (tests--) {
        solve();
    }

    return 0;
}

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