Submission #784851

#	Time	Username	Problem	Language	Result	Execution time	Memory
784851		marvinthang	Sightseeing in Kyoto (JOI22_kyoto)	C++17	100 / 100	24 ms	7884 KiB

kyoto

/*************************************
*    author: marvinthang             *
*    created: 16.07.2023 22:17:42    *
*************************************/

#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--; )
#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 << '}'; }

struct Line {
	long long a, b;
	Line(long long a, long long b): a(a), b(b) {}
	long long eval(int x) {
		return a * x + b;
	}
};

// end of template

const int MAX = 5e5 + 5;

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

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

long double inter(Line a, Line b) {
	return (long double) (b.b - a.b) / (a.a - b.a);
}

struct ConvexHullTrick {
    vector <Line> lines;
    int ptr;
    ConvexHullTrick(): ptr(0) {}
    bool bad(Line a, Line b, Line c) {
        return inter(c, a) > inter(b, a);
    }
    void addLine(long long a, long long b) {
        Line l(a, b);
        while (lines.size() >= 2 && bad(lines.end()[-2], lines.back(), l)) lines.pop_back();
        lines.push_back(l);
    }
    Line getMin(long long x) {
        if (ptr >= (int) lines.size()) ptr = (int) lines.size() - 1;
        while (ptr < (int) lines.size() - 1 && lines[ptr].eval(x) > lines[ptr + 1].eval(x)) ++ptr;
        return lines[ptr];
    }
};

void process(void) {
	ConvexHullTrick cht_a, cht_b;
	REP(i, N) cht_a.addLine(i, A[i]);
	REP(i, M) cht_b.addLine(i, B[i]);
	int i = 0, j = 0;
	N = cht_a.lines.size();
	M = cht_b.lines.size();
	long long res = 0;
	while (i < N - 1 || j < M - 1) {
		if (i == N - 1 || (j < M - 1 && inter(cht_a.lines[i], cht_a.lines[i + 1]) < inter(cht_b.lines[j], cht_b.lines[j + 1]))) {
			res += (cht_b.lines[j + 1].a - cht_b.lines[j].a) * A[cht_a.lines[i].a];
			++j;
		} else {
			res += (cht_a.lines[i + 1].a - cht_a.lines[i].a) * B[cht_b.lines[j].a];
			++i;
		}
	}
	cout << res << '\n';
}

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

Compilation message (stderr)

kyoto.cpp: In function 'int main()':
kyoto.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); }
      |                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
kyoto.cpp:108:2: note: in expansion of macro 'file'
  108 |  file("kyoto");
      |  ^~~~
kyoto.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); }
      |                                                                                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
kyoto.cpp:108:2: note: in expansion of macro 'file'
  108 |  file("kyoto");
      |  ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 30 / 30
• Subtask 3: 60 / 60