oj.uz

Submission #883279

# Submission time Handle Problem Language Result Execution time Memory
883279 2023-12-05T04:02:11 Z nguyentunglam Beads and wires (APIO14_beads) C++17
57 / 100
 74 ms 28744 KB 
#include<bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define endl "\n"
using namespace std;

const int N = 1e5 + 10;

int f[N], g[N], h[N];

int _f[N], _g[N], _h[N];

int maxw[2][N];

vector<pair<int, int> > adj[N];

void dfs(int u, int p) {
  maxw[0][u] = maxw[1][u] = -1e9;
  for(auto &[v, w] : adj[u]) if (v != p) {
    dfs(v, u);
    h[v] = max(f[v], g[v] + w);
    f[u] += h[v];
    maxw[1][u] = max(maxw[1][u], w + f[v] - h[v]);
    if (maxw[0][u] < maxw[1][u]) swap(maxw[0][u], maxw[1][u]);
  }
  g[u] = f[u] + maxw[0][u];
}

void _dfs(int u, int p, int w, int pre_cost) {
  if (p) {
    _f[u] = f[p] - h[u] + _h[p];
    int cost = maxw[0][p];
    if (w + f[u] - h[u] == cost) cost = maxw[1][p];
    cost = max(cost, pre_cost);
    _g[u] = _f[u] + cost;
    _h[u] = max(_f[u], _g[u] + w);
    int new_cost = w + _f[u] - _h[u];
    pre_cost = new_cost;
  }

  for(auto &[v, next_w] : adj[u]) if (v != p) {
    _dfs(v, u, next_w, pre_cost);
  }
}

int32_t main() {
  #define task ""

  cin.tie(0) -> sync_with_stdio(0);

  if (fopen("task.inp", "r")) {
    freopen("task.inp", "r", stdin);
    freopen("task.out", "w", stdout);
  }

  if (fopen(task".inp", "r")) {
    freopen (task".inp", "r", stdin);
    freopen (task".out", "w", stdout);
  }

  int n; cin >> n;

  for(int i = 1; i < n; i++) {
    int a, b, c; cin >> a >> b >> c;
    adj[a].emplace_back(b, c);
    adj[b].emplace_back(a, c);
  }

  dfs(1, 0);

  _dfs(1, 0, 0, -1e9);

  int ans = 0;

  for(int i = 1; i <= n; i++) {
    ans = max(ans, f[i] + _h[i]);
  }

  cout << ans;
}

Compilation message

beads.cpp: In function 'int32_t main()':
beads.cpp:51:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |     freopen("task.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
beads.cpp:52:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |     freopen("task.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
beads.cpp:56:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |     freopen (task".inp", "r", stdin);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
beads.cpp:57:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |     freopen (task".out", "w", stdout);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 2 ms 4852 KB Output is correct
4 Correct 1 ms 4700 KB Output is correct
5 Correct 1 ms 4700 KB Output is correct
6 Correct 1 ms 4700 KB Output is correct
7 Correct 2 ms 4700 KB Output is correct
8 Correct 1 ms 4708 KB Output is correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 1 ms 4700 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 2 ms 4852 KB Output is correct
4 Correct 1 ms 4700 KB Output is correct
5 Correct 1 ms 4700 KB Output is correct
6 Correct 1 ms 4700 KB Output is correct
7 Correct 2 ms 4700 KB Output is correct
8 Correct 1 ms 4708 KB Output is correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 1 ms 4700 KB Output is correct
13 Correct 1 ms 4700 KB Output is correct
14 Correct 1 ms 4700 KB Output is correct
15 Correct 1 ms 4700 KB Output is correct
16 Correct 1 ms 4700 KB Output is correct
17 Correct 1 ms 4700 KB Output is correct
18 Correct 1 ms 4752 KB Output is correct
19 Correct 1 ms 4700 KB Output is correct
20 Correct 1 ms 4696 KB Output is correct
21 Correct 1 ms 4696 KB Output is correct
22 Correct 1 ms 4700 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 2 ms 4852 KB Output is correct
4 Correct 1 ms 4700 KB Output is correct
5 Correct 1 ms 4700 KB Output is correct
6 Correct 1 ms 4700 KB Output is correct
7 Correct 2 ms 4700 KB Output is correct
8 Correct 1 ms 4708 KB Output is correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 1 ms 4700 KB Output is correct
13 Correct 1 ms 4700 KB Output is correct
14 Correct 1 ms 4700 KB Output is correct
15 Correct 1 ms 4700 KB Output is correct
16 Correct 1 ms 4700 KB Output is correct
17 Correct 1 ms 4700 KB Output is correct
18 Correct 1 ms 4752 KB Output is correct
19 Correct 1 ms 4700 KB Output is correct
20 Correct 1 ms 4696 KB Output is correct
21 Correct 1 ms 4696 KB Output is correct
22 Correct 1 ms 4700 KB Output is correct
23 Correct 2 ms 4956 KB Output is correct
24 Correct 2 ms 4956 KB Output is correct
25 Correct 2 ms 4956 KB Output is correct
26 Correct 4 ms 5212 KB Output is correct
27 Correct 4 ms 5240 KB Output is correct
28 Correct 3 ms 5396 KB Output is correct
29 Correct 4 ms 5212 KB Output is correct
30 Correct 3 ms 5212 KB Output is correct
31 Correct 5 ms 5724 KB Output is correct

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 2 ms 4852 KB Output is correct
4 Correct 1 ms 4700 KB Output is correct
5 Correct 1 ms 4700 KB Output is correct
6 Correct 1 ms 4700 KB Output is correct
7 Correct 2 ms 4700 KB Output is correct
8 Correct 1 ms 4708 KB Output is correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 1 ms 4700 KB Output is correct
13 Correct 1 ms 4700 KB Output is correct
14 Correct 1 ms 4700 KB Output is correct
15 Correct 1 ms 4700 KB Output is correct
16 Correct 1 ms 4700 KB Output is correct
17 Correct 1 ms 4700 KB Output is correct
18 Correct 1 ms 4752 KB Output is correct
19 Correct 1 ms 4700 KB Output is correct
20 Correct 1 ms 4696 KB Output is correct
21 Correct 1 ms 4696 KB Output is correct
22 Correct 1 ms 4700 KB Output is correct
23 Correct 2 ms 4956 KB Output is correct
24 Correct 2 ms 4956 KB Output is correct
25 Correct 2 ms 4956 KB Output is correct
26 Correct 4 ms 5212 KB Output is correct
27 Correct 4 ms 5240 KB Output is correct
28 Correct 3 ms 5396 KB Output is correct
29 Correct 4 ms 5212 KB Output is correct
30 Correct 3 ms 5212 KB Output is correct
31 Correct 5 ms 5724 KB Output is correct
32 Correct 17 ms 7772 KB Output is correct
33 Correct 22 ms 8032 KB Output is correct
34 Correct 21 ms 7768 KB Output is correct
35 Runtime error 74 ms 28744 KB Execution killed with signal 11
36 Halted 0 ms 0 KB -