Submission #878764

#	Time	Username	Problem	Language	Result	Execution time	Memory
878764		marvinthang	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	150 ms	129108 KiB

skyscraper

/*************************************
*    author: marvinthang             *
*    created: 03.02.2023 14:54:32    *
*************************************/

#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        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; --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 T> scan_op(vector <T>)  { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> scan_op(pair <U, V>)  { return in >> u.fi >> u.se; }
template <class U, class V> print_op(pair <U, V>)  { return out << '(' << u.first << ", " << u.second << ')'; }
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 <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 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 MAX = 5e4 + 4;
const int BLOCK_SIZE = 150;

int N, M, B[MAX], P[MAX];

void init(void) {
	cin >> N >> M;
	REP(i, M) cin >> B[i] >> P[i];
}

bool exist[BLOCK_SIZE][BLOCK_SIZE];
vector <pair <int, int>> adj[MAX];
pair <int, int> rev_id[MAX * BLOCK_SIZE];
int dist[MAX * BLOCK_SIZE + MAX];
int id[BLOCK_SIZE][MAX];
bool inQueue[MAX * BLOCK_SIZE + MAX];

void process(void) {
	REP(i, M) if (P[i] < BLOCK_SIZE) exist[P[i]][B[i] % P[i]] = true;
	int nn = N;
	FOR(i, 1, BLOCK_SIZE - 1) REP(j, i) if (exist[i][j]) for (int k = j; k < N; k += i) {
		id[i][k] = nn++;
		rev_id[id[i][k] - N] = make_pair(i, k);
	}
	REP(i, M) {
		if (P[i] >= BLOCK_SIZE) {
			for (int j = 1, k = B[i]; (k -= P[i]) >= 0; ++j) 
				adj[B[i]].push_back(make_pair(j, k));
			for (int j = 1; B[i] + j * P[i] < N; ++j) 
				adj[B[i]].push_back(make_pair(j, B[i] + j * P[i]));
		} else adj[B[i]].push_back(make_pair(0, id[P[i]][B[i]]));
	}
	queue <int> q;
	memset(dist, 0x3f, sizeof(dist));
	dist[B[0]] = 0;
	q.push(B[0]);
	inQueue[B[0]] = true;
	while (!q.empty()) {
		int u = q.front(); q.pop();
		inQueue[u] = false;
		if (u >= N) {
			auto &[p, b] = rev_id[u - N];
			if (minimize(dist[b], dist[u]) && !inQueue[b]) {
				q.push(b);
				inQueue[b] = true;
			}
			if (b >= p && minimize(dist[id[p][b - p]], dist[u] + 1) && !inQueue[id[p][b - p]]) {
				q.push(id[p][b - p]);
				inQueue[id[p][b - p]] = true;
			}
			if (b + p < N && minimize(dist[id[p][b + p]], dist[u] + 1) && !inQueue[id[p][b + p]]) {
				q.push(id[p][b + p]);
				inQueue[id[p][b + p]] = true;
			}
		} else {
			for (auto &[w, v]: adj[u]) if (minimize(dist[v], dist[u] + w) && !inQueue[v]) {
				q.push(v);
				inQueue[v] = true;
			}
		}
	}
	cout << (dist[B[1]] < 1e9 ? dist[B[1]] : -1) << '\n';
}

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

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:27:61: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |     #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:111:2: note: in expansion of macro 'file'
  111 |  file("skyscraper");
      |  ^~~~
skyscraper.cpp:27:94: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |     #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:111:2: note: in expansion of macro 'file'
  111 |  file("skyscraper");
      |  ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 43 / 43