Submission #469389

#	Time	Username	Problem	Language	Result	Execution time	Memory
469389		chienyu_xiong	Robots (APIO13_robots)	C++17	60 / 100	515 ms	163844 KiB

robots

#pragma GCC optimize("O3")

#include <bits/stdc++.h>

using namespace std;

#define F first
#define S second

#define pb push_back
#define mp make_pair

#define int long long

#define pii pair<int, int>

#define all(_) begin(_), end(_)

#define smx(y, x) ((y) = max(x, y))
#define smn(y, x) ((y) = min(x, y))

void setIO() {
    ios_base::sync_with_stdio(false);

    cin.tie(nullptr);
    cout.tie(nullptr);
}

const int N = 5e2 + 3;
const int M = 1e1 + 1;
const int K = 3e5 + 0;

const int inf = 9e17;
const int mod = 1e9 + 7; 

int xyz = 1; // test cases

int x, n, m;

int vis[N][N][4];
pii nxt[N][N][4];

int dp[N][N][M][M];

string grd[N];

vector<pii> que[K];

bool bnd(int y, int x) {
    return (y >= 0 && y < n) && (x >= 0 && x < m) && grd[y][x] != 'x';
}

pii dfs(int y, int x, int d) {
    if (grd[y][x] == 'A') d = (d + 3) % 4;
    if (grd[y][x] == 'C') d = (d + 1) % 4;

    if (vis[y][x][d])
        return nxt[y][x][d];

    vis[y][x][d] = 1;
    nxt[y][x][d] = {-1, -1};

    switch (d) {
        case 0: // N
            nxt[y][x][d] = bnd(y - 1, x) ? dfs(y - 1, x, d) : mp(y, x);
            break;
        case 1: // E
            nxt[y][x][d] = bnd(y, x + 1) ? dfs(y, x + 1, d) : mp(y, x);
            break;
        case 2: // S
            nxt[y][x][d] = bnd(y + 1, x) ? dfs(y + 1, x, d) : mp(y, x);
            break;
        case 3: // W
            nxt[y][x][d] = bnd(y, x - 1) ? dfs(y, x - 1, d) : mp(y, x);
            break;
        default: break;
    }

    return nxt[y][x][d];
}

void run() {
    cin >> x >> m >> n;

    for (int i = 0; i < n; i++)
        cin >> grd[i];

    for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
    for (int k = 0; k < 4; k++) {
        if (bnd(i, j)) dfs(i, j, k);
    }
    }
    }
    
    for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
    for (int r = 1; r <= x; r++)
    for (int l = 1; l <= x; l++)
        dp[i][j][l][r] = inf;

    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            if ('1' <= grd[i][j] && grd[i][j] <= '9')
                dp[i][j][grd[i][j] - '0'][grd[i][j] - '0'] = 0;

    /* for (int i = 0; i < n; i++) */
    /*     for (int j = 0; j < m; j++) */
    /*         for (int k = 0; k < 4; k++) */
    /*             cout << i << " " << j << " " << k << ": " << nxt[i][j][k].F << " | " << nxt[i][j][k].S << endl; */

    for (int w = 0; w < x; w++) {
        for (int v = 1; v + w <= x; v++) {
            int l = v;
            int r = v + w;

            for (int i = 0; i < n; i++)
                for (int j = 0; j < m; j++)
                    for (int k = l; k < r; k++)
                        smn(dp[i][j][l][r], dp[i][j][l][k + 0] + dp[i][j][k + 1][r]);
        }

        for (int v = 1; v + w <= x; v++) {
            int l = v;
            int r = v + w;

            for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                if (dp[i][j][l][r] < K)
                    que[dp[i][j][l][r]].pb({i, j});

            for (int d = 0; d < K; d++) {
                for (auto [y, x] : que[d]) {
                    if (dp[y][x][l][r] != d) continue;

                    for (int k = 0; k < 4; k++) {
                        int ny;
                        int nx;
                        tie(ny, nx) = nxt[y][x][k];

                        int val = d + 1;
                        if (bnd(ny, nx) && dp[ny][nx][l][r] > val && val < K)
                            que[dp[ny][nx][l][r] = val].pb({ny, nx});
                    }
                }
                que[d].clear();
            }
        }
    }

    int ans = inf;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            smn(ans, dp[i][j][1][x]);
        }
    }

    cout << (ans == inf ? -1 : ans) << endl;
}

signed main() {
    setIO();

    while (xyz--)
        run();

#ifdef LOCAL
    cin.clear(); cout.flush(); system("pause");
#endif

    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 0 / 40