Submission #38911

#	Time	Username	Problem	Language	Result	Execution time	Memory
38911		qoo2p5	Robots (APIO13_robots)	C++14	60 / 100	1500 ms	124592 KiB

robots

#pragma GCC optimize("Ofast,unroll-loops,unroll-all-loops")
#pragma GCC target("sse4,tune=native")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

const int INF = (int) 1e9 + 1e6 + 123;
const ll LINF = (ll) 1e18 + 1e9 + 123;
const ld EPS = (ld) 1e-7;
const ll MOD = (ll) 1e9 + 7;

#define sz(x) (int) (x).size()
#define mp(x, y) make_pair(x, y)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lb(s, t, x) (int) (lower_bound(s, t, x) - s)
#define ub(s, t, x) (int) (upper_bound(s, t, x) - s)
#define rep(i, f, t) for (int i = f; i < t; i++)
#define per(i, f, t) for (int i = f; i >= t; i--)

ll power(ll x, ll y, ll mod = MOD) {
    if (y == 0) {
        return 1;
    }
    if (y & 1) {
        return power(x, y - 1, mod) * x % mod;
    } else {
        ll tmp = power(x, y / 2, mod);
        return tmp * tmp % mod;
    }
}

template<typename A, typename B> bool mini(A &x, const B &y) {
    if (y < x) {
        x = y;
        return true;
    }
    return false;
}

template<typename A, typename B> bool maxi(A &x, const B &y) {
    if (y > x) {
        x = y;
        return true;
    }
    return false;
}

void add(ll &x, ll y) {
	x += y;
	if (x >= MOD) x -= MOD;
	if (x < 0) x += MOD;
}

ll mult(ll x, ll y) {
	return x * y % MOD;
}

void run();

#define TASK ""

int main() {
#ifdef LOCAL
    if (strlen(TASK) > 0) {
        cerr << "Reminder: you are using file i/o, filename: " TASK "!" << endl << endl;
    }
#endif
#ifndef LOCAL
    if (strlen(TASK)) {
        freopen(TASK ".in", "r", stdin);
        freopen(TASK ".out", "w", stdout);
    }
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
#endif
    cout << fixed << setprecision(12);
    run();
    return 0;
}

// == SOLUTION == //

const int N = 10;
const int W = 505;

const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};

int n, w, h;
int dp[N][N][W][W];
string f[W];
pair<pair<int, int>, int> step[W][W][4];
pair<int, int> nxt[W][W][4];
bool used[W][W];

bool can_go(int x, int y) {
	return 0 <= x && x < h && 0 <= y && y < w && f[x][y] != 'x';
}

void dfs(int x, int y, int dir) {
	if (nxt[x][y][dir].first != -3) {
		return;
	}
	
	if (step[x][y][dir].first.first == -1) {
		nxt[x][y][dir] = {x, y};
		return;
	}
	
	nxt[x][y][dir] = {-2, -2};
	int tx = step[x][y][dir].first.first;
	int ty = step[x][y][dir].first.second;
	int tdir = step[x][y][dir].second;
	if (nxt[tx][ty][tdir].first == -2) {
		nxt[x][y][dir] = {-1, -1};
		return;
	}
	
	dfs(tx, ty, tdir);
	if (nxt[tx][ty][tdir].first == -1) {
		nxt[x][y][dir] = {-1, -1};
		return;
	}
	
	nxt[x][y][dir] = nxt[tx][ty][tdir];
}

void run() {
	cin >> n >> w >> h;
	
	rep(i, 0, N) {
		rep(j, 0, N) {
			rep(t, 0, W) {
				rep(k, 0, W) {
					dp[i][j][t][k] = INF;
				}
			}
		}
	}
	
	rep(i, 0, h) {
		cin >> f[i];
		rep(j, 0, w) {
			if ('1' <= f[i][j] && f[i][j] <= '9') {
				int id = f[i][j] - '1';
				dp[id][id + 1][i][j] = 0;
			}
		}
	}
	
	rep(i, 0, h) {
		rep(j, 0, w) {
			rep(dir, 0, 4) {
				int tdir = dir;
				if (f[i][j] == 'A') {
					tdir = (tdir + 1) % 4;
				} else if (f[i][j] == 'C') {
					tdir = (tdir + 3) % 4;
				}
				int nx = i + dx[tdir];
				int ny = j + dy[tdir];
				if (!can_go(nx, ny)) {
					step[i][j][dir] = {{-1, -1}, -1};
				} else {
					step[i][j][dir] = {{nx, ny}, tdir};
				}
				
				nxt[i][j][dir] = {-3, -3};
			}
		}
	}
	
	rep(i, 0, h) {
		rep(j, 0, w) {
			rep(dir, 0, 4) {
				dfs(i, j, dir);
			}
		}
	}
	
	priority_queue<pair<int, pair<int, int>>> q;
	
	rep(len, 1, n + 1) {
		rep(l, 0, n - len + 1) {
			int r = l + len;
			rep(k, l + 1, r) {
				rep(x, 0, h) {
					rep(y, 0, w) {
						mini(dp[l][r][x][y], dp[l][k][x][y] + dp[k][r][x][y]);
					}
				}
			}
			
			memset(used, 0, sizeof used);
			rep(x, 0, h) {
				rep(y, 0, w) {
					if (dp[l][r][x][y] != INF) {
						q.push({-dp[l][r][x][y], {x, y}});
					}
				}
			}
			
			while (!q.empty()) {
				auto it = q.top();
				q.pop();
				int x = it.second.first;
				int y = it.second.second;
				if (used[x][y]) {
					continue;
				}
				
				used[x][y] = 1;
				rep(dir, 0, 4) {
					int nx = nxt[x][y][dir].first;
					int ny = nxt[x][y][dir].second;
					if (nx != -1 && mini(dp[l][r][nx][ny], dp[l][r][x][y] + 1)) {
						q.push({-dp[l][r][nx][ny], {nx, ny}});
					}
				}
			}
		}
	}
	
	int ans = INF;
	rep(i, 0, h) {
		rep(j, 0, w) {
			mini(ans, dp[0][n][i][j]);
		}
	}
	cout << (ans == INF ? -1 : ans) << "\n";
}

Compilation message (stderr)

robots.cpp: In function 'int main()':
robots.cpp:74:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(TASK ".in", "r", stdin);
                                        ^
robots.cpp:75:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(TASK ".out", "w", stdout);
                                          ^

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