oj.uz

답안 #940070

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
940070 2024-03-07T05:03:04 Z vjudge1 Network (BOI15_net) C++17
100 / 100
 551 ms 89476 KB 
/// ITNOG
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define fast_io ios::sync_with_stdio(false);cin.tie(NULL);
#define file_io freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);
#define FOR(i,k,n) for(int i = k; i < n; ++ i)
#define debf cout<<"(0-0)\n";
#define all(x) x.begin(), x.end()
#define dec(x) cout << fixed << setprecision(x);
#define pf push_front
#define ppf pop_front
#define dash " ------- "
#define what(x) cerr << #x << " is " << x << endl;
#define eb emplace_back
//#define int short int
#define int long long
#define sz(s) (int) (s.size())
#define fl cout.flush()

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <int, pii> pip;
typedef pair <pii, int> ppi;
typedef pair <ll, ll> pll;
typedef unsigned long long ull;
typedef long double ld;

template <class T> using max_heap = priority_queue <T, vector <T>, less <T> >;
template <class T> using min_heap = priority_queue <T, vector <T>, greater <T> >;
//template <class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

constexpr int MOD = 1e9 + 7, N = 5e5 + 8, M = 1e6, SQ = 600, INF = 1e15 + 8, LGN = 22, mod = 998244353, P = 131113;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int n, leaf, subleaf[N], r1;
vector <int> adj[N];
vector <int> v[N];
vector <pii> ans;
max_heap <pii> pq;

void dfs (int u, int par = -1){
  if (adj[u].size() == 1){
    ++ leaf;
    ++ subleaf[u];
  }
  for (int i : adj[u]){
    if (i != par){
      dfs (i, u);
      subleaf[u] += subleaf[i];
    }
  }
  return;
}

void dfs2 (int u, int par = -1){
  for (int i = 0; i < adj[u].size(); ++ i){
    int x = adj[u][i];
    if (x != par){
      if (subleaf[x] > leaf / 2){
        i = INF;
        r1 = x;
        dfs2 (x, u);
      }
    }
  }
  return;
}

void dfs3 (int u, int xx = -1, int par = -1){
  if (adj[u].size() == 1){
    v[xx].pb(u);
  }
  for (int i : adj[u]){
    if (i != par){
      if (u == r1){
        dfs3 (i, i, u);
      }
      else {
        dfs3 (i, xx, u);
      }
    }
  }
  return;
}

int32_t main(){
  fast_io;
  cin >> n;
  FOR (i, 0, n - 1){
    int aa, bb;
    cin >> aa >> bb;
    adj[--aa].pb(--bb);
    adj[bb].pb(aa);
    if (adj[aa].size() > 1){
      r1 = aa;
    }
  }
  dfs (r1);
  dfs2 (r1);
  cout << (leaf + 1) / 2 << '\n';
  dfs3 (r1);
  for (int i = 0; i < n; ++ i){
    if (v[i].size()){
      pq.push({v[i].size(), i});
    }
  }
  while (pq.size()){
    if (pq.size() == 1){
      break;
    }
    pii p1 = pq.top();
    pq.pop();
    pii p2 = pq.top();
    pq.pop();
    ans.pb({v[p1.S].back(), v[p2.S].back()});
    v[p1.S].ppb();
    v[p2.S].ppb();
    -- p1.F;
    -- p2.F;
    if (p1.F){
      pq.push(p1);
    }
    if (p2.F){
      pq.push(p2);
    }
  }
  if (pq.size() == 1){
    ans.pb({v[pq.top().S].back(), r1});
  }
  for (pii i : ans){
    cout << i.F + 1 << " " << i.S + 1 << '\n';
  }
  return 0;
}

// Yesterday is history
// Tomorrow is a mystery
// but today is a gift
// That is why it is called the present

Compilation message

net.cpp: In function 'void dfs2(long long int, long long int)':
net.cpp:67:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |   for (int i = 0; i < adj[u].size(); ++ i){
      |                   ~~^~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 25176 KB Output is correct
2 Correct 5 ms 25180 KB Output is correct
3 Correct 5 ms 25224 KB Output is correct
4 Correct 10 ms 25024 KB Output is correct
5 Correct 6 ms 25176 KB Output is correct
6 Correct 5 ms 25176 KB Output is correct
7 Correct 5 ms 25180 KB Output is correct
8 Correct 5 ms 25180 KB Output is correct
9 Correct 5 ms 25268 KB Output is correct
10 Correct 5 ms 25176 KB Output is correct
11 Correct 6 ms 25180 KB Output is correct
12 Correct 6 ms 25180 KB Output is correct
13 Correct 6 ms 25260 KB Output is correct
14 Correct 6 ms 25176 KB Output is correct
15 Correct 7 ms 25432 KB Output is correct
16 Correct 6 ms 25180 KB Output is correct
17 Correct 7 ms 25176 KB Output is correct
18 Correct 6 ms 25180 KB Output is correct
19 Correct 6 ms 25176 KB Output is correct
20 Correct 6 ms 25176 KB Output is correct

Subtask #2
45.0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 25176 KB Output is correct
2 Correct 5 ms 25180 KB Output is correct
3 Correct 5 ms 25224 KB Output is correct
4 Correct 10 ms 25024 KB Output is correct
5 Correct 6 ms 25176 KB Output is correct
6 Correct 5 ms 25176 KB Output is correct
7 Correct 5 ms 25180 KB Output is correct
8 Correct 5 ms 25180 KB Output is correct
9 Correct 5 ms 25268 KB Output is correct
10 Correct 5 ms 25176 KB Output is correct
11 Correct 6 ms 25180 KB Output is correct
12 Correct 6 ms 25180 KB Output is correct
13 Correct 6 ms 25260 KB Output is correct
14 Correct 6 ms 25176 KB Output is correct
15 Correct 7 ms 25432 KB Output is correct
16 Correct 6 ms 25180 KB Output is correct
17 Correct 7 ms 25176 KB Output is correct
18 Correct 6 ms 25180 KB Output is correct
19 Correct 6 ms 25176 KB Output is correct
20 Correct 6 ms 25176 KB Output is correct
21 Correct 6 ms 25180 KB Output is correct
22 Correct 7 ms 25436 KB Output is correct
23 Correct 7 ms 25436 KB Output is correct
24 Correct 7 ms 25436 KB Output is correct
25 Correct 6 ms 25336 KB Output is correct
26 Correct 7 ms 25224 KB Output is correct
27 Correct 7 ms 25436 KB Output is correct
28 Correct 7 ms 25312 KB Output is correct
29 Correct 7 ms 25276 KB Output is correct
30 Correct 6 ms 25272 KB Output is correct
31 Correct 8 ms 25180 KB Output is correct
32 Correct 6 ms 25184 KB Output is correct
33 Correct 7 ms 25180 KB Output is correct
34 Correct 6 ms 25180 KB Output is correct
35 Correct 6 ms 25180 KB Output is correct
36 Correct 6 ms 25184 KB Output is correct
37 Correct 6 ms 25188 KB Output is correct
38 Correct 6 ms 25188 KB Output is correct
39 Correct 6 ms 25184 KB Output is correct
40 Correct 9 ms 25188 KB Output is correct
41 Correct 8 ms 25184 KB Output is correct
42 Correct 6 ms 25184 KB Output is correct
43 Correct 6 ms 25232 KB Output is correct
44 Correct 5 ms 25192 KB Output is correct
45 Correct 6 ms 25192 KB Output is correct
46 Correct 6 ms 25184 KB Output is correct
47 Correct 6 ms 25176 KB Output is correct
48 Correct 7 ms 25188 KB Output is correct
49 Correct 7 ms 25280 KB Output is correct
50 Correct 6 ms 25192 KB Output is correct
51 Correct 6 ms 25180 KB Output is correct
52 Correct 6 ms 25268 KB Output is correct
53 Correct 6 ms 25184 KB Output is correct
54 Correct 6 ms 25268 KB Output is correct
55 Correct 6 ms 25216 KB Output is correct
56 Correct 6 ms 25272 KB Output is correct
57 Correct 6 ms 25180 KB Output is correct
58 Correct 6 ms 25436 KB Output is correct

Subtask #3
37.0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 25176 KB Output is correct
2 Correct 5 ms 25180 KB Output is correct
3 Correct 5 ms 25224 KB Output is correct
4 Correct 10 ms 25024 KB Output is correct
5 Correct 6 ms 25176 KB Output is correct
6 Correct 5 ms 25176 KB Output is correct
7 Correct 5 ms 25180 KB Output is correct
8 Correct 5 ms 25180 KB Output is correct
9 Correct 5 ms 25268 KB Output is correct
10 Correct 5 ms 25176 KB Output is correct
11 Correct 6 ms 25180 KB Output is correct
12 Correct 6 ms 25180 KB Output is correct
13 Correct 6 ms 25260 KB Output is correct
14 Correct 6 ms 25176 KB Output is correct
15 Correct 7 ms 25432 KB Output is correct
16 Correct 6 ms 25180 KB Output is correct
17 Correct 7 ms 25176 KB Output is correct
18 Correct 6 ms 25180 KB Output is correct
19 Correct 6 ms 25176 KB Output is correct
20 Correct 6 ms 25176 KB Output is correct
21 Correct 6 ms 25180 KB Output is correct
22 Correct 7 ms 25436 KB Output is correct
23 Correct 7 ms 25436 KB Output is correct
24 Correct 7 ms 25436 KB Output is correct
25 Correct 6 ms 25336 KB Output is correct
26 Correct 7 ms 25224 KB Output is correct
27 Correct 7 ms 25436 KB Output is correct
28 Correct 7 ms 25312 KB Output is correct
29 Correct 7 ms 25276 KB Output is correct
30 Correct 6 ms 25272 KB Output is correct
31 Correct 8 ms 25180 KB Output is correct
32 Correct 6 ms 25184 KB Output is correct
33 Correct 7 ms 25180 KB Output is correct
34 Correct 6 ms 25180 KB Output is correct
35 Correct 6 ms 25180 KB Output is correct
36 Correct 6 ms 25184 KB Output is correct
37 Correct 6 ms 25188 KB Output is correct
38 Correct 6 ms 25188 KB Output is correct
39 Correct 6 ms 25184 KB Output is correct
40 Correct 9 ms 25188 KB Output is correct
41 Correct 8 ms 25184 KB Output is correct
42 Correct 6 ms 25184 KB Output is correct
43 Correct 6 ms 25232 KB Output is correct
44 Correct 5 ms 25192 KB Output is correct
45 Correct 6 ms 25192 KB Output is correct
46 Correct 6 ms 25184 KB Output is correct
47 Correct 6 ms 25176 KB Output is correct
48 Correct 7 ms 25188 KB Output is correct
49 Correct 7 ms 25280 KB Output is correct
50 Correct 6 ms 25192 KB Output is correct
51 Correct 6 ms 25180 KB Output is correct
52 Correct 6 ms 25268 KB Output is correct
53 Correct 6 ms 25184 KB Output is correct
54 Correct 6 ms 25268 KB Output is correct
55 Correct 6 ms 25216 KB Output is correct
56 Correct 6 ms 25272 KB Output is correct
57 Correct 6 ms 25180 KB Output is correct
58 Correct 6 ms 25436 KB Output is correct
59 Correct 394 ms 66252 KB Output is correct
60 Correct 382 ms 63744 KB Output is correct
61 Correct 6 ms 25180 KB Output is correct
62 Correct 7 ms 25264 KB Output is correct
63 Correct 330 ms 58972 KB Output is correct
64 Correct 7 ms 25436 KB Output is correct
65 Correct 15 ms 27228 KB Output is correct
66 Correct 106 ms 42432 KB Output is correct
67 Correct 500 ms 80580 KB Output is correct
68 Correct 500 ms 68088 KB Output is correct
69 Correct 16 ms 26844 KB Output is correct
70 Correct 97 ms 44996 KB Output is correct
71 Correct 407 ms 89476 KB Output is correct
72 Correct 397 ms 86728 KB Output is correct
73 Correct 62 ms 33788 KB Output is correct
74 Correct 347 ms 59080 KB Output is correct
75 Correct 29 ms 30284 KB Output is correct
76 Correct 356 ms 74136 KB Output is correct
77 Correct 350 ms 74896 KB Output is correct
78 Correct 30 ms 29276 KB Output is correct
79 Correct 551 ms 69484 KB Output is correct
80 Correct 7 ms 25464 KB Output is correct
81 Correct 124 ms 42760 KB Output is correct
82 Correct 442 ms 72760 KB Output is correct
83 Correct 392 ms 58944 KB Output is correct
84 Correct 381 ms 59932 KB Output is correct
85 Correct 345 ms 60092 KB Output is correct
86 Correct 401 ms 63680 KB Output is correct
87 Correct 401 ms 64532 KB Output is correct