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답안 #877280

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
877280 2023-11-23T05:31:24 Z mgl_diamond Janjetina (COCI21_janjetina) C++17
110 / 110
 149 ms 20032 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ii = pair<int, int>;
 
#define foru(i, l, r) for(int i=(l); i<=(r); ++i)
#define ford(i, l, r) for(int i=(l); i>=(r); --i)
#define fore(x, v) for(auto &x : v)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define file "input"

template<class T> bool minimize(T &a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T> bool maximize(T &a, T b) { if (a < b) { a = b; return 1; } return 0; }

void setIO() {
  ios::sync_with_stdio(0);
  cin.tie(0); cout.tie(0);
  if (fopen(file".inp", "r")) {
    freopen(file".inp", "r", stdin);
    freopen(file".out", "w", stdout);
  }
}

const int N = 1e5+5;

int n, k;
ll ans;
vector<ii> adj[N];

// centroid
int cent, tree_size, max_dep;
  
struct fenwick {
  int tmp;
  vector<int> bit;

  void init(int n) {
    tmp = n;
    bit = vector<int>(n+2, 0);
  }

  void update(int i, int v) {
    assert(i <= tmp);
    for(++i; i<=tmp+1; i+=i&-i) bit[i] += v;
  }

  int query(int i) {
    i = min(tmp, i);
    int ans = 0;
    for(++i; i>=1; i-=i&-i) ans += bit[i];
    return ans;
  }
} branch[N], al;

int high[N], sub[N], who[N];
bool process[N];

int get_subsize(int u, int p) {
  sub[u] = 1;
  fore(x, adj[u]) {
    int v = x.fi;
    if (v == p || process[v]) continue;
    sub[u] += get_subsize(v, u);
  }
  return sub[u];
}

int get_centroid(int u, int p) {
  fore(x, adj[u]) {
    int v = x.fi;
    if (v == p || process[v]) continue;
    if (sub[v] * 2 > tree_size) return get_centroid(v, u);
  }
  return u;
}

vector<ii> cands;

int dfs_prep(int u, int p, int mark, int mx = 0) {
  if (mx - high[u] >= k) ++ans;
  if (u != cent) {
    int ans = 0;
    who[u] = mark;
    fore(x, adj[u]) {
      int v = x.fi, w = x.se;
      if (v == p || process[v]) continue;
      cands.emplace_back(max(mx, w), v);
      high[v] = high[u] + 1;
      maximize(ans, dfs_prep(v, u, mark, max(mx, w)) + 1);
    }
    return ans;
  }
  else {
    int ans = 0;
    fore(x, adj[u]) {
      int v = x.fi, w = x.se;
      if (v == p || process[v]) continue;
      cands.emplace_back(max(mx, w), v);
      high[v] = high[u] + 1;
      int tmp = dfs_prep(v, u, mark, max(mx, w));
      maximize(ans, tmp + 1);
      branch[mark].init(tmp+1);
      ++mark;
    }
    return ans;
  }
}

void solve(int u) {
  tree_size = get_subsize(u, 0);
  cent = get_centroid(u, 0);
  cands.clear();
  high[cent] = 0;
  max_dep = dfs_prep(cent, cent, 0);
  al.init(max_dep);

  // cout << ans << "\n";
  sort(all(cands));
  fore(x, cands) {
    int j = x.fi - high[x.se] - k;
    if (j >= 0) ans += al.query(j) - branch[who[x.se]].query(j);
    // if (x.se == 2) cout << al.query(j) << "\n";
    // cout << x.fi - high[x.se] - k << "\n";
    al.update(high[x.se], 1);
    branch[who[x.se]].update(high[x.se], 1);
  } 

  // cout << cent << " " << ans << "\n";
  process[cent] = 1;
  fore(x, adj[cent]) {
    int v = x.fi, w = x.se;
    if (process[v]) continue;
    solve(v);
  }
}

int main() {
  setIO();

  cin >> n >> k;
  foru(i, 1, n-1) {
    int u, v, w;
    cin >> u >> v >> w; 
    adj[u].emplace_back(v, w);
    adj[v].emplace_back(u, w);
  }

  solve(1);  
  cout << ans*2;
}

/*
5 2
1 2 5
2 3 2
1 4 3
3 5 4
*/

Compilation message

Main.cpp: In function 'void solve(int)':
Main.cpp:134:19: warning: unused variable 'w' [-Wunused-variable]
  134 |     int v = x.fi, w = x.se;
      |                   ^
Main.cpp: In function 'void setIO()':
Main.cpp:22:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |     freopen(file".inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:23:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |     freopen(file".out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 7000 KB Output is correct
2 Correct 1 ms 7004 KB Output is correct
3 Correct 1 ms 7004 KB Output is correct
4 Correct 2 ms 7048 KB Output is correct
5 Correct 2 ms 7004 KB Output is correct
6 Correct 2 ms 7172 KB Output is correct
7 Correct 2 ms 7168 KB Output is correct
8 Correct 3 ms 7000 KB Output is correct
9 Correct 2 ms 7004 KB Output is correct
10 Correct 2 ms 7004 KB Output is correct
11 Correct 2 ms 7004 KB Output is correct
12 Correct 2 ms 7008 KB Output is correct
13 Correct 2 ms 7004 KB Output is correct
14 Correct 3 ms 7004 KB Output is correct
15 Correct 2 ms 7004 KB Output is correct
16 Correct 2 ms 7004 KB Output is correct
17 Correct 2 ms 7004 KB Output is correct
18 Correct 3 ms 7004 KB Output is correct
19 Correct 2 ms 7004 KB Output is correct
20 Correct 2 ms 7072 KB Output is correct
21 Correct 3 ms 7256 KB Output is correct
22 Correct 2 ms 7004 KB Output is correct

Subtask #2
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 7004 KB Output is correct
2 Correct 1 ms 7004 KB Output is correct
3 Correct 1 ms 7004 KB Output is correct
4 Correct 3 ms 7004 KB Output is correct
5 Correct 11 ms 8392 KB Output is correct
6 Correct 63 ms 13424 KB Output is correct
7 Correct 124 ms 19400 KB Output is correct
8 Correct 140 ms 19976 KB Output is correct
9 Correct 132 ms 19400 KB Output is correct
10 Correct 141 ms 19740 KB Output is correct
11 Correct 123 ms 19400 KB Output is correct
12 Correct 139 ms 19664 KB Output is correct
13 Correct 128 ms 19436 KB Output is correct
14 Correct 140 ms 19656 KB Output is correct
15 Correct 145 ms 19648 KB Output is correct
16 Correct 141 ms 19912 KB Output is correct
17 Correct 134 ms 19764 KB Output is correct
18 Correct 135 ms 19652 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 7000 KB Output is correct
2 Correct 1 ms 7004 KB Output is correct
3 Correct 1 ms 7004 KB Output is correct
4 Correct 2 ms 7048 KB Output is correct
5 Correct 2 ms 7004 KB Output is correct
6 Correct 2 ms 7172 KB Output is correct
7 Correct 2 ms 7168 KB Output is correct
8 Correct 3 ms 7000 KB Output is correct
9 Correct 2 ms 7004 KB Output is correct
10 Correct 2 ms 7004 KB Output is correct
11 Correct 2 ms 7004 KB Output is correct
12 Correct 2 ms 7008 KB Output is correct
13 Correct 2 ms 7004 KB Output is correct
14 Correct 3 ms 7004 KB Output is correct
15 Correct 2 ms 7004 KB Output is correct
16 Correct 2 ms 7004 KB Output is correct
17 Correct 2 ms 7004 KB Output is correct
18 Correct 3 ms 7004 KB Output is correct
19 Correct 2 ms 7004 KB Output is correct
20 Correct 2 ms 7072 KB Output is correct
21 Correct 3 ms 7256 KB Output is correct
22 Correct 2 ms 7004 KB Output is correct
23 Correct 2 ms 7004 KB Output is correct
24 Correct 1 ms 7004 KB Output is correct
25 Correct 1 ms 7004 KB Output is correct
26 Correct 3 ms 7004 KB Output is correct
27 Correct 11 ms 8392 KB Output is correct
28 Correct 63 ms 13424 KB Output is correct
29 Correct 124 ms 19400 KB Output is correct
30 Correct 140 ms 19976 KB Output is correct
31 Correct 132 ms 19400 KB Output is correct
32 Correct 141 ms 19740 KB Output is correct
33 Correct 123 ms 19400 KB Output is correct
34 Correct 139 ms 19664 KB Output is correct
35 Correct 128 ms 19436 KB Output is correct
36 Correct 140 ms 19656 KB Output is correct
37 Correct 145 ms 19648 KB Output is correct
38 Correct 141 ms 19912 KB Output is correct
39 Correct 134 ms 19764 KB Output is correct
40 Correct 135 ms 19652 KB Output is correct
41 Correct 1 ms 7000 KB Output is correct
42 Correct 124 ms 19348 KB Output is correct
43 Correct 138 ms 20032 KB Output is correct
44 Correct 139 ms 19408 KB Output is correct
45 Correct 148 ms 19736 KB Output is correct
46 Correct 149 ms 19364 KB Output is correct
47 Correct 137 ms 19776 KB Output is correct
48 Correct 129 ms 19476 KB Output is correct
49 Correct 148 ms 19780 KB Output is correct
50 Correct 141 ms 19604 KB Output is correct
51 Correct 143 ms 19608 KB Output is correct
52 Correct 60 ms 13768 KB Output is correct
53 Correct 64 ms 14096 KB Output is correct
54 Correct 55 ms 13512 KB Output is correct
55 Correct 64 ms 13876 KB Output is correct
56 Correct 63 ms 14044 KB Output is correct
57 Correct 132 ms 13276 KB Output is correct
58 Correct 144 ms 13524 KB Output is correct
59 Correct 132 ms 13772 KB Output is correct
60 Correct 134 ms 13524 KB Output is correct
61 Correct 135 ms 13732 KB Output is correct
62 Correct 106 ms 13264 KB Output is correct
63 Correct 118 ms 13512 KB Output is correct
64 Correct 130 ms 14028 KB Output is correct
65 Correct 6 ms 7664 KB Output is correct
66 Correct 1 ms 7004 KB Output is correct