답안 #51850 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
51850	2018-06-21T17:55:14 Z	mareksom	Network (BOI15_net)	C++17	100 / 100	1772 ms	210956 KB

#ifndef LOCAL
#pragma GCC optimize ("O3")
#endif

#include <bits/stdc++.h>

using namespace std;

#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
sim > struct rge { c b, e; };
sim > rge<c> range(c i, c j) { return {i, j}; }
sim > auto dud(c* x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
~debug() { cerr << endl; }
eni(!=) cerr << boolalpha << i; ris; }
eni(==) ris << range(begin(i), end(i)); }
sim, class b dor(pair < b, c > d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (c it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
sim dor(const c&) { ris; }
#endif
};
#define imie(x...) " [" #x ": " << (x) << "] "

using ld = long double;
using ll = long long;

constexpr int mod = 1000 * 1000 * 1000 + 7;
constexpr int odw2 = (mod + 1) / 2;

void OdejmijOd(int& a, int b) { a -= b; if (a < 0) a += mod; }
int Odejmij(int a, int b) { OdejmijOd(a, b); return a; }
void DodajDo(int& a, int b) { a += b; if (a >= mod) a -= mod; }
int Dodaj(int a, int b) { DodajDo(a, b); return a; }
int Mnoz(int a, int b) { return (ll) a * b % mod; }
void MnozDo(int& a, int b) { a = Mnoz(a, b); }
int Pot(int a, int b) { int res = 1; while (b) { if (b % 2 == 1) MnozDo(res, a); a = Mnoz(a, a); b /= 2; } return res; }
int Odw(int a) { return Pot(a, mod - 2); }
void PodzielDo(int& a, int b) { MnozDo(a, Odw(b)); }
int Podziel(int a, int b) { return Mnoz(a, Odw(b)); }
int Moduluj(ll x) { x %= mod; if (x < 0) x += mod; return x; }

template <typename T> T Maxi(T& a, T b) { return a = max(a, b); }
template <typename T> T Mini(T& a, T b) { return a = min(a, b); }

constexpr int nax = 500 * 1000 + 105;

int n;
set<int> graf[nax];
vector<pair<int, int>> wynik;

int Daj(int x, int oprocz) {
  assert(!graf[x].empty());
  if (graf[x].find(oprocz) == graf[x].end()) {
    if ((int) graf[x].size() >= 2) return -1;
    return *graf[x].begin();
  }
  if ((int) graf[x].size() >= 3) return -1;
  for (int y : graf[x]) {
    if (y != oprocz) {
      return y;
    }
  }
  assert(false);
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  for (int i = 1; i < n; i++) {
    int a, b;
    cin >> a >> b;
    graf[a].insert(b);
    graf[b].insert(a);
  }
  set<int> liscie;
  for (int i = 1; i <= n; i++) {
    if ((int) graf[i].size() == 1) {
      liscie.insert(i);
    }
  }
  debug() << imie(liscie);
  while (true) {
    assert((int) liscie.size() >= 2);
    const int a = *liscie.begin();
    liscie.erase(liscie.begin());
    const int b = *liscie.begin();
    liscie.erase(*liscie.begin());
    if ((int) liscie.size() <= 1) {
      wynik.emplace_back(a, b);
      liscie.insert(b);
      if ((int) liscie.size() < 2) break;
      continue;
    }
    const int c = *liscie.begin();
    liscie.erase(liscie.begin());
    int s[3] = {a, b, c};
    int w[3] = {a, b, c};
    int p[3] = {-1, -1, -1};
    while (true) {
      int daj[3];
      for (int i = 0; i < 3; i++) {
        daj[i] = Daj(w[i], p[i]);
      }
      debug() << imie(range(s, s + 3));
      debug() << imie(range(w, w + 3));
      debug() << imie(range(p, p + 3));
      debug() << imie(range(daj, daj + 3));
      for (int i = 0; i < 3; i++) {
        for (int j = i + 1; j < 3; j++) {
          if (daj[i] == -1 and daj[j] == -1) {
            if (w[i] != w[j] or (int) graf[w[i]].size() >= 4) {
              debug() << imie("JEST");
              wynik.emplace_back(s[i], s[j]);
              liscie.insert(s[3 ^ i ^ j]);
              graf[w[i]].erase(p[i]);
              graf[w[j]].erase(p[j]);
              goto out;
            }
          }
        }
      }
      for (int i = 0; i < 3; i++) {
        if (daj[i] != -1) {
          p[i] = w[i];
          w[i] = daj[i];
        }
      }
    }
    out:;
  }
  printf("%d\n", (int) wynik.size());
  for (auto& it : wynik) {
    printf("%d %d\n", it.first, it.second);
  }
  return 0;
}

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	24 ms	23800 KB	Output is correct
2	Correct	23 ms	23908 KB	Output is correct
3	Correct	27 ms	24024 KB	Output is correct
4	Correct	24 ms	24076 KB	Output is correct
5	Correct	23 ms	24124 KB	Output is correct
6	Correct	23 ms	24124 KB	Output is correct
7	Correct	27 ms	24124 KB	Output is correct
8	Correct	25 ms	24124 KB	Output is correct
9	Correct	25 ms	24144 KB	Output is correct
10	Correct	25 ms	24148 KB	Output is correct
11	Correct	25 ms	24148 KB	Output is correct
12	Correct	24 ms	24188 KB	Output is correct
13	Correct	23 ms	24248 KB	Output is correct
14	Correct	24 ms	24248 KB	Output is correct
15	Correct	24 ms	24248 KB	Output is correct
16	Correct	24 ms	24248 KB	Output is correct
17	Correct	26 ms	24248 KB	Output is correct
18	Correct	24 ms	24272 KB	Output is correct
19	Correct	24 ms	24272 KB	Output is correct
20	Correct	23 ms	24272 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	24 ms	23800 KB	Output is correct
2	Correct	23 ms	23908 KB	Output is correct
3	Correct	27 ms	24024 KB	Output is correct
4	Correct	24 ms	24076 KB	Output is correct
5	Correct	23 ms	24124 KB	Output is correct
6	Correct	23 ms	24124 KB	Output is correct
7	Correct	27 ms	24124 KB	Output is correct
8	Correct	25 ms	24124 KB	Output is correct
9	Correct	25 ms	24144 KB	Output is correct
10	Correct	25 ms	24148 KB	Output is correct
11	Correct	25 ms	24148 KB	Output is correct
12	Correct	24 ms	24188 KB	Output is correct
13	Correct	23 ms	24248 KB	Output is correct
14	Correct	24 ms	24248 KB	Output is correct
15	Correct	24 ms	24248 KB	Output is correct
16	Correct	24 ms	24248 KB	Output is correct
17	Correct	26 ms	24248 KB	Output is correct
18	Correct	24 ms	24272 KB	Output is correct
19	Correct	24 ms	24272 KB	Output is correct
20	Correct	23 ms	24272 KB	Output is correct
21	Correct	24 ms	24272 KB	Output is correct
22	Correct	31 ms	24560 KB	Output is correct
23	Correct	30 ms	24560 KB	Output is correct
24	Correct	26 ms	24600 KB	Output is correct
25	Correct	26 ms	24628 KB	Output is correct
26	Correct	27 ms	24660 KB	Output is correct
27	Correct	27 ms	24660 KB	Output is correct
28	Correct	31 ms	24660 KB	Output is correct
29	Correct	26 ms	24660 KB	Output is correct
30	Correct	23 ms	24660 KB	Output is correct
31	Correct	25 ms	24660 KB	Output is correct
32	Correct	22 ms	24660 KB	Output is correct
33	Correct	23 ms	24660 KB	Output is correct
34	Correct	23 ms	24660 KB	Output is correct
35	Correct	24 ms	24660 KB	Output is correct
36	Correct	25 ms	24660 KB	Output is correct
37	Correct	27 ms	24660 KB	Output is correct
38	Correct	24 ms	24660 KB	Output is correct
39	Correct	27 ms	24660 KB	Output is correct
40	Correct	25 ms	24660 KB	Output is correct
41	Correct	23 ms	24660 KB	Output is correct
42	Correct	24 ms	24660 KB	Output is correct
43	Correct	24 ms	24660 KB	Output is correct
44	Correct	23 ms	24660 KB	Output is correct
45	Correct	24 ms	24660 KB	Output is correct
46	Correct	26 ms	24660 KB	Output is correct
47	Correct	26 ms	24660 KB	Output is correct
48	Correct	24 ms	24660 KB	Output is correct
49	Correct	25 ms	24660 KB	Output is correct
50	Correct	23 ms	24660 KB	Output is correct
51	Correct	22 ms	24660 KB	Output is correct
52	Correct	24 ms	24660 KB	Output is correct
53	Correct	24 ms	24688 KB	Output is correct
54	Correct	22 ms	24688 KB	Output is correct
55	Correct	25 ms	24700 KB	Output is correct
56	Correct	23 ms	24700 KB	Output is correct
57	Correct	24 ms	24708 KB	Output is correct
58	Correct	25 ms	24840 KB	Output is correct

Subtask #3
37.0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	24 ms	23800 KB	Output is correct
2	Correct	23 ms	23908 KB	Output is correct
3	Correct	27 ms	24024 KB	Output is correct
4	Correct	24 ms	24076 KB	Output is correct
5	Correct	23 ms	24124 KB	Output is correct
6	Correct	23 ms	24124 KB	Output is correct
7	Correct	27 ms	24124 KB	Output is correct
8	Correct	25 ms	24124 KB	Output is correct
9	Correct	25 ms	24144 KB	Output is correct
10	Correct	25 ms	24148 KB	Output is correct
11	Correct	25 ms	24148 KB	Output is correct
12	Correct	24 ms	24188 KB	Output is correct
13	Correct	23 ms	24248 KB	Output is correct
14	Correct	24 ms	24248 KB	Output is correct
15	Correct	24 ms	24248 KB	Output is correct
16	Correct	24 ms	24248 KB	Output is correct
17	Correct	26 ms	24248 KB	Output is correct
18	Correct	24 ms	24272 KB	Output is correct
19	Correct	24 ms	24272 KB	Output is correct
20	Correct	23 ms	24272 KB	Output is correct
21	Correct	24 ms	24272 KB	Output is correct
22	Correct	31 ms	24560 KB	Output is correct
23	Correct	30 ms	24560 KB	Output is correct
24	Correct	26 ms	24600 KB	Output is correct
25	Correct	26 ms	24628 KB	Output is correct
26	Correct	27 ms	24660 KB	Output is correct
27	Correct	27 ms	24660 KB	Output is correct
28	Correct	31 ms	24660 KB	Output is correct
29	Correct	26 ms	24660 KB	Output is correct
30	Correct	23 ms	24660 KB	Output is correct
31	Correct	25 ms	24660 KB	Output is correct
32	Correct	22 ms	24660 KB	Output is correct
33	Correct	23 ms	24660 KB	Output is correct
34	Correct	23 ms	24660 KB	Output is correct
35	Correct	24 ms	24660 KB	Output is correct
36	Correct	25 ms	24660 KB	Output is correct
37	Correct	27 ms	24660 KB	Output is correct
38	Correct	24 ms	24660 KB	Output is correct
39	Correct	27 ms	24660 KB	Output is correct
40	Correct	25 ms	24660 KB	Output is correct
41	Correct	23 ms	24660 KB	Output is correct
42	Correct	24 ms	24660 KB	Output is correct
43	Correct	24 ms	24660 KB	Output is correct
44	Correct	23 ms	24660 KB	Output is correct
45	Correct	24 ms	24660 KB	Output is correct
46	Correct	26 ms	24660 KB	Output is correct
47	Correct	26 ms	24660 KB	Output is correct
48	Correct	24 ms	24660 KB	Output is correct
49	Correct	25 ms	24660 KB	Output is correct
50	Correct	23 ms	24660 KB	Output is correct
51	Correct	22 ms	24660 KB	Output is correct
52	Correct	24 ms	24660 KB	Output is correct
53	Correct	24 ms	24688 KB	Output is correct
54	Correct	22 ms	24688 KB	Output is correct
55	Correct	25 ms	24700 KB	Output is correct
56	Correct	23 ms	24700 KB	Output is correct
57	Correct	24 ms	24708 KB	Output is correct
58	Correct	25 ms	24840 KB	Output is correct
59	Correct	1281 ms	90260 KB	Output is correct
60	Correct	1423 ms	103388 KB	Output is correct
61	Correct	25 ms	103388 KB	Output is correct
62	Correct	28 ms	103388 KB	Output is correct
63	Correct	1170 ms	103388 KB	Output is correct
64	Correct	28 ms	103388 KB	Output is correct
65	Correct	47 ms	103388 KB	Output is correct
66	Correct	263 ms	103388 KB	Output is correct
67	Correct	683 ms	103388 KB	Output is correct
68	Correct	737 ms	107640 KB	Output is correct
69	Correct	46 ms	107640 KB	Output is correct
70	Correct	478 ms	107640 KB	Output is correct
71	Correct	1693 ms	143268 KB	Output is correct
72	Correct	1772 ms	146728 KB	Output is correct
73	Correct	296 ms	146728 KB	Output is correct
74	Correct	1085 ms	146728 KB	Output is correct
75	Correct	117 ms	146728 KB	Output is correct
76	Correct	1666 ms	163832 KB	Output is correct
77	Correct	1753 ms	171612 KB	Output is correct
78	Correct	99 ms	171612 KB	Output is correct
79	Correct	702 ms	171612 KB	Output is correct
80	Correct	28 ms	171612 KB	Output is correct
81	Correct	389 ms	171612 KB	Output is correct
82	Correct	1589 ms	180204 KB	Output is correct
83	Correct	1092 ms	180204 KB	Output is correct
84	Correct	1096 ms	186236 KB	Output is correct
85	Correct	1266 ms	193060 KB	Output is correct
86	Correct	1263 ms	204512 KB	Output is correct
87	Correct	1260 ms	210956 KB	Output is correct

답안 #51850

Compilation message

Subtask #1 18.0 / 18.0

Subtask #2 45.0 / 45.0

Subtask #3 37.0 / 37.0

Subtask #1
18.0 / 18.0

Subtask #2
45.0 / 45.0

Subtask #3
37.0 / 37.0