Submission #1127625

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127625		ALTAKEXE	Robots (APIO13_robots)	C++17	0 / 100	0 ms	328 KiB

robots

#include <bits/stdc++.h>
#define ll long long int
using namespace std;
const int INF = 1e9;
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
vector<string> s(500);
bool ok(int x, int y, int w, int h)
{
        return x >= 0 && x < h && y >= 0 && y < w && s[x][y] != 'x';
}
vector<vector<int>> BFS(int w, int h)
{
        vector<vector<int>> d(w * h, vector<int>(w * h, INF));
        for (int i = 0; i < w * h; i++)
        {
                int sx = i / w, sy = i % w;
                if (s[sx][sy] == 'x')
                        continue;
                queue<pair<int, int>> q;
                q.push({sx, sy});
                d[i][i] = 0;
                while (!q.empty())
                {
                        auto [x, y] = q.front();
                        q.pop();
                        int t = x * w + y;
                        for (int k = 0; k < 4; k++)
                        {
                                int xx = x, yy = y, cnt = 0;
                                while (ok(xx + dx[k], yy + dy[k], w, h))
                                {
                                        xx += dx[k];
                                        yy += dy[k];
                                        cnt++;
                                        if (d[i][xx * w + yy] > d[i][t] + 1)
                                        {
                                                d[i][xx * w + yy] = d[i][t] + 1;
                                                q.push({xx, yy});
                                        }
                                }
                        }
                }
        }
        return d;
}
int main()
{
        int n, w, h;
        cin >> n >> w >> h;
        vector<pair<int, int>> ind(n + 1);
        for (int i = 0; i < h; i++)
        {
                cin >> s[i];
                for (int j = 0; j < w; j++)
                {
                        if (isdigit(s[i][j]))
                                ind[s[i][j] - '0'] = {i, j};
                }
        }
        vector<vector<int>> d = BFS(w, h);
        vector<vector<vector<int>>> dp(n + 1, vector<vector<int>>(n + 1, vector<int>(w * h, INF)));
        for (int i = 1; i <= n; ++i)
                dp[i][i][ind[i].first * w + ind[i].second] = 0;
        for (int len = 2; len <= n; ++len)
        {
                for (int l = 1; l + len - 1 <= n; ++l)
                {
                        int r = l + len - 1;
                        for (int i = 0; i < w * h; i++)
                        {
                                if (i / w >= h || i % w >= w || s[i / w][i % w] == 'x')
                                        continue;
                                for (int k = l; k < r; k++)
                                {
                                        for (int q = 0; q < w * h; q++)
                                        {
                                                for (int e = 0; e < w * h; e++)
                                                {
                                                        if (d[q][i] == INF || d[e][i] == INF)
                                                                continue;
                                                        dp[l][r][i] = min(dp[l][r][i], dp[l][k][q] + dp[k + 1][r][e] + d[q][i] + d[e][i]);
                                                }
                                        }
                                }
                        }
                }
        }
        ll ans = INF;
        for (int i = 0; i < w * h; i++)
                ans = min(ans, (ll)dp[1][n][i]);
        cout << (ans == INF ? -1 : ans) << endl;
        return 0;
}

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