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Submission #46886

# Submission time Handle Problem Language Result Execution time Memory
46886 2018-04-24T14:14:02 Z cheater2k Robots (APIO13_robots) C++17
60 / 100
 1500 ms 163840 KB 
#include <bits/stdc++.h>
using namespace std;

const int N = 505;
const int INF = 1e9;
const int dx[] = {-1, 0, +1, 0};
const int dy[] = {0, +1, 0, -1};
typedef pair<int,int> ii;

int n, r, c;
char a[N][N];
int dis[N][N][10][10];
ii dest[N][N][4];

struct state { 
	int dis; int x; int y; int l; int r; 
	bool operator < (const state &other) const {
		return dis > other.dis;
	}
};

bool inside(int x, int y) { return x >= 1 && x <= r && y >= 1 && y <= c; }

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);

	cin >> n >> c >> r;
	for (int i = 1; i <= r; ++i) {
		for (int j = 1; j <= c; ++j) {
			cin >> a[i][j];
		}
	}
	
	// calculate dest[][][]
	for (int i = 1; i <= r; ++i) {
		for (int j = 1; j <= c; ++j) {
			for (int dir = 0; dir < 4; ++dir) {
				if (dest[i][j][dir] == make_pair(0,0)) { // was not visited
					// dfs using stack
					int destx, desty;
					int x = i, y = j, curdir = dir;
					stack < pair<ii, int> > st; // ((x, y), dir)
					while(true) {
						if (dest[x][y][curdir] != make_pair(0, 0)) {
							destx = dest[x][y][curdir].first;
							desty = dest[x][y][curdir].second;
							break;
						}

						st.push(make_pair(ii(x, y), curdir));
						int ndir = curdir;
						if (a[x][y] == 'A') ndir = (curdir + 3) % 4;
						if (a[x][y] == 'C') ndir = (curdir + 1) % 4;

						int nx = x + dx[ndir], ny = y + dy[ndir];
						if (!inside(nx, ny) || a[nx][ny] == 'x') {
							destx = x; desty = y; break;
						}

						x = nx; y = ny; curdir = ndir;
					}

					while(!st.empty()) {
						x = st.top().first.first, y = st.top().first.second, curdir = st.top().second;
						st.pop();
						dest[x][y][curdir] = {destx, desty};
					}
				}
			}
		}
	}	
	
	// BFS
	priority_queue <state> q;
	for (int i = 1; i <= r; ++i) for (int j = 1; j <= c; ++j) {
		for (int l = 1; l <= n; ++l) for (int r = 1; r <= n; ++r) {
			dis[i][j][l][r] = INF;
		}
	}
	for (int i = 1; i <= r; ++i) for (int j = 1; j <= c; ++j) {
		if (a[i][j] >= '1' && a[i][j] <= '9') {
			dis[i][j][a[i][j] - '0'][a[i][j] - '0'] = 0;
			q.push({0, i, j, a[i][j] - '0', a[i][j] - '0'});
		}
	}

	while(!q.empty()) {
		auto t = q.top(); q.pop();
		int x = t.x, y = t.y, l = t.l, r = t.r;
		if (l == 1 && r == n) {
			printf("%d\n", dis[x][y][l][r]); return 0;
		}
		if (t.dis != dis[x][y][l][r]) continue;
		
		//cerr << x << ' ' << y << "[" << l << ' ' << r << "] -> " << dis[x][y][l][r] << endl;

		// push
		for (int dir = 0; dir < 4; ++dir) {
			int nx = dest[x][y][dir].first, ny = dest[x][y][dir].second;
			if (dis[nx][ny][l][r] > dis[x][y][l][r] + 1) {
				dis[nx][ny][l][r] = dis[x][y][l][r] + 1;
				q.push({dis[nx][ny][l][r], nx, ny, l, r});
			};
		}

		// merge
		for (int k = 1; k <= l - 1; ++k) if (dis[x][y][k][l - 1] <= t.dis) {
			if (dis[x][y][k][r] > dis[x][y][l][r] + dis[x][y][k][l - 1]) {
				dis[x][y][k][r] = dis[x][y][l][r] + dis[x][y][k][l - 1];
				q.push({dis[x][y][k][r], x, y, k, r});
			}
		}
		for (int k = r + 1; k <= n; ++k) if (dis[x][y][r + 1][k] <= t.dis) {
			if (dis[x][y][l][k] > dis[x][y][l][r] + dis[x][y][r + 1][k]) {
				dis[x][y][l][k] = dis[x][y][l][r] + dis[x][y][r + 1][k];
				q.push({dis[x][y][l][k], x, y, l, k});
			}
		}
	}
	
	printf("-1\n");
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 440 KB Output is correct
3 Correct 2 ms 440 KB Output is correct
4 Correct 2 ms 544 KB Output is correct
5 Correct 2 ms 544 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 440 KB Output is correct
3 Correct 2 ms 440 KB Output is correct
4 Correct 2 ms 544 KB Output is correct
5 Correct 2 ms 544 KB Output is correct
6 Correct 2 ms 544 KB Output is correct
7 Correct 2 ms 544 KB Output is correct
8 Correct 2 ms 544 KB Output is correct
9 Correct 2 ms 544 KB Output is correct
10 Correct 2 ms 544 KB Output is correct

Subtask #3
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 440 KB Output is correct
3 Correct 2 ms 440 KB Output is correct
4 Correct 2 ms 544 KB Output is correct
5 Correct 2 ms 544 KB Output is correct
6 Correct 2 ms 544 KB Output is correct
7 Correct 2 ms 544 KB Output is correct
8 Correct 2 ms 544 KB Output is correct
9 Correct 2 ms 544 KB Output is correct
10 Correct 2 ms 544 KB Output is correct
11 Correct 377 ms 45796 KB Output is correct
12 Correct 77 ms 45796 KB Output is correct
13 Correct 84 ms 45796 KB Output is correct
14 Correct 1269 ms 61076 KB Output is correct
15 Correct 171 ms 61076 KB Output is correct

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 440 KB Output is correct
3 Correct 2 ms 440 KB Output is correct
4 Correct 2 ms 544 KB Output is correct
5 Correct 2 ms 544 KB Output is correct
6 Correct 2 ms 544 KB Output is correct
7 Correct 2 ms 544 KB Output is correct
8 Correct 2 ms 544 KB Output is correct
9 Correct 2 ms 544 KB Output is correct
10 Correct 2 ms 544 KB Output is correct
11 Correct 377 ms 45796 KB Output is correct
12 Correct 77 ms 45796 KB Output is correct
13 Correct 84 ms 45796 KB Output is correct
14 Correct 1269 ms 61076 KB Output is correct
15 Correct 171 ms 61076 KB Output is correct
16 Correct 342 ms 108100 KB Output is correct
17 Execution timed out 1587 ms 163840 KB Time limit exceeded
18 Halted 0 ms 0 KB -