Submission #726025

#	Time	Username	Problem	Language	Result	Execution time	Memory
726025		vjudge1	Robots (APIO13_robots)	C++17	100 / 100	511 ms	67020 KiB

robots

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

const int dr[] = {-1, 0, +1, 0};
const int dc[] = {0, +1, 0, -1};

enum {
        STAND = 4,
        UP = 0,
        RIGHT = 1,
        DOWN = 2,
        LEFT = 3,
        NOT_GOOD = 1000000000
};

int n, m, k;
char a[500][500];
int c[500][500];
int f[9][9][500][500];
int g[4][500][500];
vector<pair<int, int>> adj[500][500];

int DP(int z, int i, int j) {
        if (g[z][i][j] != -1) return g[z][i][j];
        g[z][i][j] = NOT_GOOD;
        int zz = (z + c[i][j]) % 4;
        int ii = i + dr[zz];
        int jj = j + dc[zz];
        if (ii < 0 || ii >= n || jj < 0 || jj >= m || a[ii][jj] == 'x') return g[z][i][j] = i * m + j;
        return g[z][i][j] = DP(zz, ii, jj);
}

class data_t {
       public:
        int d, i, j;
        data_t(int d, int i, int j) : d(d), i(i), j(j) {}

        bool operator<(const data_t& other) const {
                return d > other.d;
        }
};

int main() {
        cin >> k >> m >> n;
        for (int i = 0; i < n; i++)
                for (int j = 0; j < m; j++) cin >> a[i][j];
        for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                        for (int l = 0; l < k; l++)
                                for (int r = l; r < k; r++) f[l][r][i][j] = NOT_GOOD;
                        if (a[i][j] == 'A') {
                                c[i][j] = +3;
                        } else if (a[i][j] == 'C') {
                                c[i][j] = +1;
                        } else if (a[i][j] == 'x') {
                                c[i][j] = -1;
                        } else if (a[i][j] == '.') {
                                c[i][j] = 0;
                        } else {
                                a[i][j] -= '0' + 1;
                                assert(0 <= a[i][j] && a[i][j] < k);
                                f[a[i][j]][a[i][j]][i][j] = 0;
                        }
                }
        }

        memset(g, -1, sizeof g);

        for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                        if (a[i][j] == 'x') continue;
                        for (int z = 0; z < 4; z++) {
                                if (DP(z, i, j) == NOT_GOOD) continue;
                                int ii = DP(z, i, j) / m;
                                int jj = DP(z, i, j) % m;

                                adj[i][j].emplace_back(ii, jj);
                        }
                }
        }

        for (int r = 0; r < k; r++) {
                for (int l = r; l >= 0; l--) {
                        vector<data_t> best;
                        for (int i = 0; i < n; i++) {
                                for (int j = 0; j < m; j++) {
                                        if (a[i][j] == 'x') continue;
                                        for (int mid = l; mid < r; mid++) f[l][r][i][j] = min(f[l][r][i][j], f[l][mid][i][j] + f[mid + 1][r][i][j]);
                                        if (f[l][r][i][j] != NOT_GOOD) best.emplace_back(f[l][r][i][j], i, j);
                                }
                        }
                        sort(best.begin(), best.end());
                        deque<data_t> q;
                        while (best.size() || q.size()) {
                                if (q.empty() || (best.size() && best.back().d <= q.front().d)) q.emplace_front(best.back()), best.pop_back();
                                data_t cur = q.front();
                                q.pop_front();
                                if (f[l][r][cur.i][cur.j] != cur.d) continue;
                                for (auto [ii, jj] : adj[cur.i][cur.j]) {
                                        if (f[l][r][ii][jj] > cur.d + 1) {
                                                f[l][r][ii][jj] = cur.d + 1;
                                                q.emplace_back(f[l][r][ii][jj], ii, jj);
                                        }
                                }
                        }
                }
        }

        int res = NOT_GOOD;
        for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                        if (a[i][j] != 'x') res = min(res, f[0][k - 1][i][j]);
                }
        }
        cout << (res == NOT_GOOD ? -1 : res);
}

Compilation message (stderr)

robots.cpp: In function 'int main()':
robots.cpp:62:41: warning: array subscript has type 'char' [-Wchar-subscripts]
   62 |                                 f[a[i][j]][a[i][j]][i][j] = 0;
      |                                   ~~~~~~^
robots.cpp:62:50: warning: array subscript has type 'char' [-Wchar-subscripts]
   62 |                                 f[a[i][j]][a[i][j]][i][j] = 0;
      |                                            ~~~~~~^

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 40 / 40