Submission #261608

#	Time	Username	Problem	Language	Result	Execution time	Memory
261608		DS007	Robots (APIO13_robots)	C++14	100 / 100	875 ms	109688 KiB

robots

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

const int N = 9, W = 500;
int dp[N][N][W][W], pt[W][W], nxt[W][W][5];
vector<int> adj[W * W];
bool explored[W][W][5];
string a[W];
int n, w, h;

int dy[] = {0, 1, 0, -1, 0};
int dx[] = {0, 0, 1, 0, -1};

bool check(int i, int j) {
    if (i < 0 || j < 0 || i >= h || j >= w || a[i][j] == 'x')
        return false;
    return true;
}

int dfs(int i, int j, int dir) {
    if (explored[i][j][dir])
        return nxt[i][j][dir];

    explored[i][j][dir] = true;
    nxt[i][j][dir] = pt[i][j];
    if (a[i][j] != 'A' && a[i][j] != 'C' && a[i][j] != 'x') {
        if (check(i + dx[dir], j + dy[dir]))
            return nxt[i][j][dir] = dfs(i + dx[dir], j + dy[dir], dir);
        else
            return nxt[i][j][dir] = pt[i][j];
    }

    if (a[i][j] == 'C') {
        int nd = dir + 1;
        if (nd == 5)
            nd = 1;

        if (check(i + dx[nd], j + dy[nd]))
            return nxt[i][j][dir] = dfs(i + dx[nd], j + dy[nd], nd);
        else
            return nxt[i][j][dir] = pt[i][j];
    }

    if (a[i][j] == 'A') {
        int nd = dir - 1;
        if (nd == 0)
            nd = 4;

        if (check(i + dx[nd], j + dy[nd]))
            return nxt[i][j][dir] = dfs(i + dx[nd], j + dy[nd], nd);
        else
            return nxt[i][j][dir] = pt[i][j];
    }

    return -1;
}

void dijkstra(int i, int j) {
    vector<int> dist[w * h];
    bool explored[w * h] = {};

    for (int k = 0; k < h; k++) {
        for (int l = 0; l < w; l++)
            if (a[k][l] != 'x' && dp[i][j][k][l] < w * h)
                dist[dp[i][j][k][l]].push_back(pt[k][l]);
    }

    for (int i_ = 0; i_ < w * h; i_++) {
        for (int j_ : dist[i_]) {
            if (explored[j_])
                continue;

            explored[j_] = true;
            for (int k : adj[j_]) {
                if (dp[i][j][k / w][k % w] > i_ + 1)
                    dp[i][j][k / w][k % w] = i_ + 1, dist[i_ + 1].push_back(k);
            }
        }
    }
}

int solveTestCase() {
    cin >> n >> w >> h;
    for (int i = 0; i < h; i++) cin >> a[i];

    for (int i = 0; i < h; i++){
        for (int j = 0; j < w; j++)
            pt[i][j] = w * i + j;
    }

    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            if (!explored[i][j][1])
                dfs(i, j, 1);
            if (!explored[i][j][2])
                dfs(i, j, 2);
            if (!explored[i][j][3])
                dfs(i, j, 3);
            if (!explored[i][j][4])
                dfs(i, j, 4);

            adj[pt[i][j]].push_back(nxt[i][j][1]);
            adj[pt[i][j]].push_back(nxt[i][j][2]);
            adj[pt[i][j]].push_back(nxt[i][j][3]);
            adj[pt[i][j]].push_back(nxt[i][j][4]);
        }
    }

    //cerr << check(0 + dx[3], 0 + dy[3]) << "\n";
    //cerr << nxt[0][0][1] << " " << nxt[0][0][2] << " " << nxt[0][0][3] << " " << nxt[0][0][4] << "\n";

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < h; k++) {
                for (int l = 0; l < w; l++)
                dp[i][j][k][l] = 1e9;
            }
        }
    }

    for (int i = 0; i < n; i++) {
        for (int k = 0; k < h; k++) {
            for (int l = 0; l < w; l++) {
                if (a[k][l] - '0' == i + 1)
                    dp[i][i][k][l] = 0;
            }
        }

        dijkstra(i, i);
    }

    //for (int k = 0; k < h; k++) {
    //    for (int l = 0; l < w; l++)
    //        cerr << dp[0][0][k][l] << " ";
    //    cerr << "\n";
    //}

    for (int dif = 1; dif < n; dif++) {
        for (int i = 0; i < n; i++) {
            int j = i + dif;
            if (j >= n)
                continue;

            for (int x = i; x < j; x++) {
                for (int k = 0; k < h; k++) {
                    for (int l = 0; l < w; l++)
                        dp[i][j][k][l] = min(dp[i][j][k][l], dp[i][x][k][l] + dp[x + 1][j][k][l]);
                }
            }

            dijkstra(i, j);
        }
    }

    int ans = 1e9;
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++)
            ans = min(ans, dp[0][n - 1][i][j]);
    }

    cout << (ans == 1e9 ? -1 : ans);
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int t = 1;
    //cin >> t;
    while (t--)
        solveTestCase();
}

Compilation message (stderr)

robots.cpp: In function 'int solveTestCase()':
robots.cpp:162:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^

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