Submission #288996

#	Time	Username	Problem	Language	Result	Execution time	Memory
288996		Tangent	Aliens (IOI16_aliens)	C++17	4 / 100	1 ms	384 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>

using namespace std;

//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;
// typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
// find_by_order(), order_of_key()

typedef long long ll;
typedef long double dd;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<dd, dd> pdd;
typedef vector<int> vii;
typedef vector<ll> vll;
typedef vector<dd> vdd;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<pdd> vpdd;
typedef vector<vii> vvii;
typedef vector<vll> vvll;
typedef vector<vdd> vvdd;
typedef vector<vpii> vvpii;
typedef vector<vpll> vvpll;
typedef vector<vpdd> vvpdd;
typedef vector<bool> vb;

const int inf = 1 << 30;

#define rep(i, n) for (ll i = 0; i < n; i++)
#define ffor(i, a, b) for(ll i = a; i < b; i++)
#define forin(x, a) for (auto &x: a)
#define all(x) x.begin(), x.end()

#ifdef TEST
#define dbg(x) cout << #x << ": " << x << '\n';
#define dbgc(x) cout << #x << ":"; forin(a, x) { cout << " " << a; } cout << endl;
#define tassert(x) assert(x);
#else
#define dbg(x)
#define dbgc(x)
#define tassert(x)
#endif

auto cmp = [](pll a, pll b) {
  return (a.first == b.first ? b.second < a.second : a.first < b.first);
};

long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {
  set<pll, decltype(cmp)> segs(cmp);
  rep(i, n) {
    segs.emplace(min(r[i], c[i]), max(r[i], c[i]) + 1);
  }

  ll res = 0;
  pll last = {-1, -1};
  ll l;
  map<ll, ll> stoe;
  forin(seg, segs) {
    if (seg.second <= last.second) {
      continue;
    }
    res += (seg.second - seg.first) * (seg.second - seg.first);
    l = min(last.second, seg.second) - seg.first;
    if (l > 0) {
      res -= l * l;
    }
    stoe[seg.first] = seg.second;
    last = seg;
  }

  last = {-1, -1};
  ll area;
  map<pll, ll> lookup;
  set<tuple<ll, ll, ll>> pq;
  forin(seg, stoe) {
    if (last.first != -1) {
      if (seg.first < last.second) {
        area = 2 * (seg.first - last.first) * (seg.second - last.second);
      } else {
        area = 2 * (seg.first - last.first) * (seg.second - last.second) - (seg.first - last.second) * (seg.first - last.second);
      }
      assert(area > 0);
      pq.emplace(area, last.first, seg.first);
      lookup[{last.first, seg.first}] = area;
    }
    last = seg;
  }
  while (stoe.size() > k) {
    auto &[area, a, b] = *pq.begin();
    pq.erase(pq.begin());
    res += area;
    if (stoe.begin()->first < a) {
      ll aa = prev(stoe.find(a))->first;
      pll p = {aa, a};
      pq.erase({lookup[p], aa, a});
      lookup[p] += 2 * (a - aa) * (stoe[b] - stoe[a]);
      pq.emplace(lookup[p], aa, a);
    }
    if (stoe.rend()->second > stoe[b]) {
      ll bb = next(stoe.find(b))->first;
      pll p = {b, bb};
      pq.erase({lookup[p], b, bb});
      lookup[p] += 2 * (b - a) * (stoe[bb] - stoe[b]);
      pq.emplace(lookup[p], b, bb);
    }
    stoe[a] = stoe[b];
    stoe.erase(b);
  }

  return res;
}

Compilation message (stderr)

aliens.cpp: In function 'long long int take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:92:22: warning: comparison of integer expressions of different signedness: 'std::map<long long int, long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   92 |   while (stoe.size() > k) {
      |          ~~~~~~~~~~~~^~~

• Subtask 1: 4 / 4
• Subtask 2: 0 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40