Submission #892683

#	Time	Username	Problem	Language	Result	Execution time	Memory
892683		marvinthang	Bodyguard (JOI21_bodyguard)	C++17	100 / 100	4520 ms	915512 KiB

bodyguard

/*************************************
*    author: marvinthang             *
*    created: 25.12.2023 20:42:18    *
*************************************/

#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)  { return a > b ? a = b, true : false; }
template <class A, class B> bool maximize(A &a, B b)  { return a < b ? a = b, true : false; }

const long long INF = 1e18;

struct Line {
    long long a, b;
    Line(long long a = 0, long long b = INF): a(a), b(b) {}
    long long eval(long long x) { return a * x + b; }
};
struct ConvexHullTrick {
    vector <Line> lines;
    bool bad(Line a, Line b, Line c) { return (long double) (c.b - a.b) / (a.a - c.a) > (long double) (b.b - a.b) / (a.a - b.a); }
    void addLine(long long a, long long b) {
        Line l(a, b);
        while (!lines.empty() && lines.back().a <= l.a) lines.pop_back();
        while (lines.size() >= 2 && bad(lines.end()[-2], lines.back(), l)) lines.pop_back();
        lines.push_back(l);
    }
    void clear(void) {
    	lines.clear();
    }
    long long getMax(long long x) {
    	if (lines.empty()) return 0;
    	long long res = 0;
        int l = 0, r = (int) lines.size() - 2;
        while (l <= r) {
        	int m = (l + r) >> 1;
        	long long cur_1 = lines[m].eval(x);
        	long long cur_2 = lines[m + 1].eval(x);
        	maximize(res, max(cur_1, cur_2));
        	if (cur_1 < cur_2) l = m + 2;
        	else r = m - 1;
        }
        maximize(res, lines[r + 1].eval(x));
        return res;
    }
};
using CHT = ConvexHullTrick;

// end of template

void process(void) {
	int n, q; cin >> n >> q;
	vector <long long> x(n), y(n), u(n), v(n), c(n);
	vector <long long> cx, cy;
	REP(i, n) {
		long long t, a, b;
		cin >> t >> a >> b >> c[i]; c[i] /= 2;
		x[i] = t + a; 
		y[i] = t - a;
		u[i] = t + abs(a - b) + b;
		v[i] = t + abs(a - b) - b;
		cx.push_back(x[i]); cx.push_back(u[i]);
		cy.push_back(y[i]); cy.push_back(v[i]);
	}
	sort(ALL(cx)); cx.erase(unique(ALL(cx)), cx.end());
	sort(ALL(cy)); cy.erase(unique(ALL(cy)), cy.end());

	vector max_hor(cx.size(), vector<int>(cy.size()));
	vector max_ver(cx.size(), vector<int>(cy.size()));
	vector dp(cx.size(), vector<long long>(cy.size()));
	REP(i, n) {
		x[i] = lower_bound(ALL(cx), x[i]) - cx.begin();
		y[i] = lower_bound(ALL(cy), y[i]) - cy.begin();
		u[i] = lower_bound(ALL(cx), u[i]) - cx.begin();
		v[i] = lower_bound(ALL(cy), v[i]) - cy.begin();
		if (x[i] == u[i]) {
			FOR(p, y[i], v[i]) maximize(max_ver[x[i]][p], c[i]);
		} else {
			FOR(p, x[i], u[i]) maximize(max_hor[p][y[i]], c[i]);
		}
	}

	REPD(x, cx.size()) REPD(y, cy.size()) {
		if (y + 1 < (int) cy.size()) maximize(dp[x][y], dp[x][y + 1] + 1LL * (cy[y + 1] - cy[y]) * max_ver[x][y]);
		if (x + 1 < (int) cx.size()) maximize(dp[x][y], dp[x + 1][y] + 1LL * (cx[x + 1] - cx[x]) * max_hor[x][y]);
	}

	vector queriesAt(cx.size(), vector(cy.size(), vector<int>()));
	vector <long long> s(q), t(q);
	REP(i, q) {
		long long p, q; cin >> p >> q; 
		s[i] = p + q; t[i] = p - q;
		int u = lower_bound(ALL(cx), s[i]) - cx.begin();
		int v = lower_bound(ALL(cy), t[i]) - cy.begin();
		if (u == (int) cx.size() || v == (int) cy.size()) continue;
		queriesAt[u][v].push_back(i);
	}

	CHT cht;
	vector <long long> res(q);
	REP(x, cx.size()) {
		cht.clear();
		REPD(y, cy.size()) {
			cht.addLine(x ? max_hor[x - 1][y] : 0, dp[x][y]);
			for (int i: queriesAt[x][y]) {
				maximize(res[i], cht.getMax(cx[x] - s[i]));
			}

		}
	}
	REP(y, cy.size()) {
		cht.clear();
		REPD(x, cx.size()) {
			cht.addLine(y ? max_ver[x][y - 1] : 0, dp[x][y]);
			for (int i: queriesAt[x][y]) maximize(res[i], cht.getMax(cy[y] - t[i]));
		}
	}
	REP(i, q) cout << res[i] << '\n';
}

int main(void) {
	ios_base::sync_with_stdio(false); cin.tie(nullptr); // cout.tie(nullptr);
	file("JOI21_bodyguard");
	// int t; cin >> t; while (t--)
	process();
	// cerr << "Time elapsed: " << TIME << " s.\n";
	return (0^0);
}

Compilation message (stderr)

bodyguard.cpp: In function 'int main()':
bodyguard.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); }
      |                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bodyguard.cpp:156:2: note: in expansion of macro 'file'
  156 |  file("JOI21_bodyguard");
      |  ^~~~
bodyguard.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); }
      |                                                                                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bodyguard.cpp:156:2: note: in expansion of macro 'file'
  156 |  file("JOI21_bodyguard");
      |  ^~~~

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 15 / 15
• Subtask 4: 20 / 20
• Subtask 5: 52 / 52