Submission #879723

#	Time	Username	Problem	Language	Result	Execution time	Memory
879723		marvinthang	Robots (APIO13_robots)	C++17	100 / 100	495 ms	53584 KiB

robots

/*************************************
*    author: marvinthang             *
*    created: 28.11.2023 08:29:17    *
*************************************/

#include <bits/stdc++.h>

using namespace std;

#define                  fi  first
#define                  se  second
#define                left  ___left
#define               right  ___right
#define                TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define             MASK(i)  (1LL << (i))
#define           BIT(x, i)  ((x) >> (i) & 1)
#define  __builtin_popcount  __builtin_popcountll
#define              ALL(v)  (v).begin(), (v).end()
#define           REP(i, n)  for (int i = 0, _n = (n); i < _n; ++i)
#define          REPD(i, n)  for (int i = (n); i-- > 0; )
#define        FOR(i, a, b)  for (int i = (a), _b = (b); i < _b; ++i) 
#define       FORD(i, b, a)  for (int i = (b), _a = (a); --i >= _a; ) 
#define       FORE(i, a, b)  for (int i = (a), _b = (b); i <= _b; ++i) 
#define      FORDE(i, b, a)  for (int i = (b), _a = (a); i >= _a; --i) 
#define        scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define       print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
    #include "debug.h"
#else
    #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
    #define DB(...) 23
    #define db(...) 23
    #define debug(...) 23
#endif

template <class U, class V> scan_op(pair <U, V>)  { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>)  { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>)  { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")";  else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
template <class A, class B> bool minimize(A &a, B b)  { if (a > b) { a = b; return true; } return false; }
template <class A, class B> bool maximize(A &a, B b)  { if (a < b) { a = b; return true; } return false; }

// end of template

const int INF = 1e9;

// anti-clockwise
const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};

void process(void) {
	int n, h, w; cin >> n >> w >> h;
	vector <string> grid(h); cin >> grid;
	auto inside = [&] (int u, int v) {
		return 0 <= u && u < h && 0 <= v && v < w && grid[u][v] != 'x';
	};
	vector id(h, vector(w, -1));
	int cnt = 0;
	REP(x, h) REP(y, w) if (inside(x, y)) {
		bool valid = false;
		if ('0' <= grid[x][y] && grid[x][y] <= '9') {
			--grid[x][y];
			valid = true;
		}
		if (!valid) REP(d, 4) if (!inside(x + dx[d], y + dy[d])) {
			valid = true;
			break;
		}
		if (valid) id[x][y] = cnt++;
	}
	vector <vector <int>> adj(cnt);
	REP(x, h) REP(y, w) if (inside(x, y)) {
		REP(d, 4) if (!inside(x + dx[d], y + dy[d])) {
			int u = x, v = y, cur_d = d;
			while (inside(u, v)) {
				if ((u != x || v != y) && id[u][v] >= 0) adj[id[u][v]].push_back(id[x][y]);
				if (grid[u][v] == 'A') cur_d = (cur_d + 3) & 3;
				else if (grid[u][v] == 'C') cur_d = (cur_d + 1) & 3;
				u -= dx[cur_d]; v -= dy[cur_d];
			}
		}
	}
	vector dp(n, vector(n, vector(cnt, INF)));
	REP(x, h) REP(y, w) if ('0' <= grid[x][y] && grid[x][y] <= '9') dp[grid[x][y] - '0'][grid[x][y] - '0'][id[x][y]] = 0;
	REPD(l, n) FOR(r, l, n) {
		vector <pair <int, int>> v;
		REP(i, cnt) {
			FOR(k, l, r) minimize(dp[l][r][i], dp[l][k][i] + dp[k + 1][r][i]);
			if (dp[l][r][i] < INF) v.emplace_back(dp[l][r][i], i);
		}
		sort(ALL(v));
		vector <int> cur, nxt;
		int ptr = 0;
		while (!cur.empty() || ptr < size(v)) {
			if (cur.empty()) {
				if (dp[l][r][v[ptr].se] == v[ptr].fi) cur.push_back(v[ptr++].se);
				else {
					ptr++;
					continue;
				}
			}
			while (ptr < size(v) && dp[l][r][v[ptr].se] == dp[l][r][cur.back()]) cur.push_back(v[ptr++].se);
			nxt.clear();
			while (!cur.empty()) {
				int u = cur.back(); cur.pop_back();
				for (int v: adj[u]) if (minimize(dp[l][r][v], dp[l][r][u] + 1)) nxt.push_back(v);
			}
			cur = move(nxt);
		}
	}
	int res = INF;
	REP(i, cnt) minimize(res, dp[0][n - 1][i]);
	cout << (res == INF ? -1 : res) << '\n';
}

int main(void) {
	ios_base::sync_with_stdio(false); cin.tie(nullptr); // cout.tie(nullptr);
	file("robots");
	// int t; cin >> t; while (t--)
	process();
	// cerr << "Time elapsed: " << TIME << " s.\n";
	return (0^0);
}

Compilation message (stderr)

robots.cpp: In function 'void process()':
robots.cpp:96:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   96 |   while (!cur.empty() || ptr < size(v)) {
      |                          ~~~~^~~~~~~~~
robots.cpp:104:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  104 |    while (ptr < size(v) && dp[l][r][v[ptr].se] == dp[l][r][cur.back()]) cur.push_back(v[ptr++].se);
      |           ~~~~^~~~~~~~~
robots.cpp: In function 'int main()':
robots.cpp:30:61: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
robots.cpp:120:2: note: in expansion of macro 'file'
  120 |  file("robots");
      |  ^~~~
robots.cpp:30:94: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
robots.cpp:120:2: note: in expansion of macro 'file'
  120 |  file("robots");
      |  ^~~~

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