Submission #37699

#	Time	Username	Problem	Language	Result	Execution time	Memory
37699		funcsr	Bulldozer (JOI17_bulldozer)	C++14	100 / 100	978 ms	100352 KiB

bulldozer

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cmath>
#include <iomanip>
#include <cassert>
#include <bitset>
using namespace std;

typedef pair<int, int> P;
typedef pair<P, int> P2;
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(c) (c).begin(), (c).end()
#define uniq(c) c.erase(unique(all(c)), (c).end())
#define index(xs, x) (int)(lower_bound(all(xs), x) - xs.begin())
#define _1 first
#define _2 second
#define pb push_back
#define INF 1145141919
#define MOD 1000000007
struct Node {
  long long s, l, r, m;
  Node(long long s, long long l, long long r, long long m) : s(s), l(l), r(r), m(m) {}
  Node(long long w) : Node(w, max(w, 0LL), max(w, 0LL), max(w, 0LL)) {}
  Node() : Node(0) {}
};
Node op(const Node &a, const Node &b) {
  return Node(
    a.s + b.s,
    max(a.l, a.s + b.l),
    max(b.r, b.s + a.r),
    max(max(a.m, b.m), a.r + b.l)
  );
}

#define MAX_N (1<<11)
Node seg[MAX_N*2-1];
void update(int k, Node x) {
  k += MAX_N-1;
  seg[k] = x;
  while (k > 0) {
    k = (k-1)/2;
    seg[k] = op(seg[k*2+1], seg[k*2+2]);
  }
}

int N;
int X[2000], Y[2000], W[2000];

struct Rel {
  int p, q;
  Rel(int p, int q) : p(p), q(q) {
    if (q < 0) p = -p, q = -q;
  }
  bool operator<(const Rel& b) const { return 1LL*p*b.q < 1LL*b.p*q; }
  bool operator==(const Rel& b) const { return 1LL*p*b.q == 1LL*b.p*q; }
};
int pos[2000], rev[2000];
vector<int> G[1999000];

signed main() {
  ios::sync_with_stdio(false); cin.tie(0);
  cin >> N;
  vector<P2> ps;
  rep(i, N) {
    int x, y, w;
    cin >> x >> y >> w;
    ps.pb(P2(P(x, -y), w));
  }
  sort(all(ps));
  rep(i, N) {
    X[i] = ps[i]._1._1, Y[i] = -ps[i]._1._2, W[i] = ps[i]._2;
    pos[i] = i, rev[i] = i;
    update(i, Node(W[i]));
  }
  if (N == 1) {
    cout << max(W[0], 0) << "\n";
    return 0;
  }

  vector<pair<Rel, P>> lines;
  rep(i, N) rep(j, i) {
    Rel r = Rel(-1, 0);
    if (X[i] != X[j]) r = Rel(Y[i]-Y[j], X[i]-X[j]);
    lines.pb(make_pair(r, P(i, j)));
  }
  sort(all(lines));
  long long m = seg[0].m;
  vector<long long> bs;
  Rel a = lines[0]._1;
  vector<int> ln;
  rep(e, lines.size()) {
    if (!(a == lines[e]._1)) a = lines[e]._1;
    P p = lines[e]._2;
    bs.pb(1LL*Y[p._1]*a.q-1LL*X[p._1]*a.p);
    ln.pb(pos[p._1]);
    ln.pb(pos[p._2]);

    if (e+1 >= lines.size() || !(a == lines[e+1]._1)) {
      sort(all(bs)); uniq(bs);
      sort(all(ln)); uniq(ln);
      for (int p : ln) {
        int k = index(bs, 1LL*Y[rev[p]]*a.q-1LL*X[rev[p]]*a.p);
        G[k].pb(p);
      }
      rep(i, bs.size()) {
        vector<int> &ps = G[i];
        rep(i, ps.size()/2) {
          int a = rev[ps[i]], b = rev[ps[(int)ps.size()-1-i]];
          swap(pos[a], pos[b]);
          rev[pos[a]] = a;
          rev[pos[b]] = b;
          update(pos[a], Node(W[a]));
          update(pos[b], Node(W[b]));
        }
      }
      rep(i, bs.size()) G[i].clear();
      bs.clear();
      ln.clear();
      m = max(m, seg[0].m);
    }
  }
  cout << m << "\n";
  return 0;
}

Compilation message (stderr)

bulldozer.cpp: In function 'int main()':
bulldozer.cpp:18:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define rep(i, n) for (int i=0; i<(n); i++)
                                  ^
bulldozer.cpp:98:3: note: in expansion of macro 'rep'
   rep(e, lines.size()) {
   ^~~
bulldozer.cpp:105:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (e+1 >= lines.size() || !(a == lines[e+1]._1)) {
         ~~~~^~~~~~~~~~~~~~~
bulldozer.cpp:18:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define rep(i, n) for (int i=0; i<(n); i++)
                                  ^
bulldozer.cpp:112:7: note: in expansion of macro 'rep'
       rep(i, bs.size()) {
       ^~~
bulldozer.cpp:18:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define rep(i, n) for (int i=0; i<(n); i++)
                                  ^
bulldozer.cpp:114:9: note: in expansion of macro 'rep'
         rep(i, ps.size()/2) {
         ^~~
bulldozer.cpp:18:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define rep(i, n) for (int i=0; i<(n); i++)
                                  ^
bulldozer.cpp:123:7: note: in expansion of macro 'rep'
       rep(i, bs.size()) G[i].clear();
       ^~~

• Subtask 1: 5 / 5
• Subtask 2: 20 / 20
• Subtask 3: 35 / 35
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20