#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 200005;
const ll INF = 1e9;
ll dp[N][2][2];
vector<pair<int, int>> adj[N];
void dfs(int u, int p) {
ll best0 = -INF, best1 = -INF, best01 = -INF, best11 = -INF;
for (auto e : adj[u]) {
int v, w; tie(v, w) = e;
if (v == p) continue; dfs(v, u);
ll tmp = max(dp[v][0][0], dp[v][1][0] + w);
dp[u][0][0] += tmp;
best11 = max(best11, max(dp[v][0][1], dp[v][1][1] + w) - tmp);
best01 = max(best01, max(best0 + max(dp[v][0][0],
dp[v][0][1]) + w, best1 + dp[v][0][0] + w) - tmp);
best0 = max(best0, dp[v][0][0] + w - tmp);
best1 = max(best1, dp[v][0][1] + w - tmp);
}
dp[u][0][1] = dp[u][1][0] = dp[u][1][1] = dp[u][0][0];
dp[u][1][0] += best0; dp[u][1][1] += best1;
dp[u][0][1] = max(dp[u][0][1] + best11, dp[u][0][0] + best01);
}
int main() {
cin.tie(0)->sync_with_stdio(0);
int n; cin >> n;
for (int i = 1; i < n; i++) {
int u, v, w;
cin >> u >> v >> w;
adj[u].emplace_back(v, w);
adj[v].emplace_back(u, w);
}
dfs(1, 0); cout << max(dp[1][0][0], dp[1][0][1]);
}
Compilation message
beads.cpp: In function 'void dfs(int, int)':
beads.cpp:17:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
17 | if (v == p) continue; dfs(v, u);
| ^~
beads.cpp:17:31: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
17 | if (v == p) continue; dfs(v, u);
| ^~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4940 KB |
Output is correct |
2 |
Correct |
3 ms |
4940 KB |
Output is correct |
3 |
Correct |
3 ms |
4912 KB |
Output is correct |
4 |
Correct |
2 ms |
4940 KB |
Output is correct |
5 |
Correct |
2 ms |
4940 KB |
Output is correct |
6 |
Correct |
3 ms |
4940 KB |
Output is correct |
7 |
Correct |
3 ms |
5020 KB |
Output is correct |
8 |
Correct |
2 ms |
4940 KB |
Output is correct |
9 |
Correct |
2 ms |
4940 KB |
Output is correct |
10 |
Correct |
2 ms |
4972 KB |
Output is correct |
11 |
Correct |
2 ms |
4940 KB |
Output is correct |
12 |
Correct |
2 ms |
4940 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4940 KB |
Output is correct |
2 |
Correct |
3 ms |
4940 KB |
Output is correct |
3 |
Correct |
3 ms |
4912 KB |
Output is correct |
4 |
Correct |
2 ms |
4940 KB |
Output is correct |
5 |
Correct |
2 ms |
4940 KB |
Output is correct |
6 |
Correct |
3 ms |
4940 KB |
Output is correct |
7 |
Correct |
3 ms |
5020 KB |
Output is correct |
8 |
Correct |
2 ms |
4940 KB |
Output is correct |
9 |
Correct |
2 ms |
4940 KB |
Output is correct |
10 |
Correct |
2 ms |
4972 KB |
Output is correct |
11 |
Correct |
2 ms |
4940 KB |
Output is correct |
12 |
Correct |
2 ms |
4940 KB |
Output is correct |
13 |
Correct |
2 ms |
4940 KB |
Output is correct |
14 |
Correct |
3 ms |
4940 KB |
Output is correct |
15 |
Correct |
3 ms |
4940 KB |
Output is correct |
16 |
Correct |
3 ms |
4940 KB |
Output is correct |
17 |
Correct |
3 ms |
4940 KB |
Output is correct |
18 |
Correct |
3 ms |
4940 KB |
Output is correct |
19 |
Correct |
3 ms |
4940 KB |
Output is correct |
20 |
Correct |
3 ms |
4940 KB |
Output is correct |
21 |
Correct |
3 ms |
4940 KB |
Output is correct |
22 |
Correct |
3 ms |
4940 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4940 KB |
Output is correct |
2 |
Correct |
3 ms |
4940 KB |
Output is correct |
3 |
Correct |
3 ms |
4912 KB |
Output is correct |
4 |
Correct |
2 ms |
4940 KB |
Output is correct |
5 |
Correct |
2 ms |
4940 KB |
Output is correct |
6 |
Correct |
3 ms |
4940 KB |
Output is correct |
7 |
Correct |
3 ms |
5020 KB |
Output is correct |
8 |
Correct |
2 ms |
4940 KB |
Output is correct |
9 |
Correct |
2 ms |
4940 KB |
Output is correct |
10 |
Correct |
2 ms |
4972 KB |
Output is correct |
11 |
Correct |
2 ms |
4940 KB |
Output is correct |
12 |
Correct |
2 ms |
4940 KB |
Output is correct |
13 |
Correct |
2 ms |
4940 KB |
Output is correct |
14 |
Correct |
3 ms |
4940 KB |
Output is correct |
15 |
Correct |
3 ms |
4940 KB |
Output is correct |
16 |
Correct |
3 ms |
4940 KB |
Output is correct |
17 |
Correct |
3 ms |
4940 KB |
Output is correct |
18 |
Correct |
3 ms |
4940 KB |
Output is correct |
19 |
Correct |
3 ms |
4940 KB |
Output is correct |
20 |
Correct |
3 ms |
4940 KB |
Output is correct |
21 |
Correct |
3 ms |
4940 KB |
Output is correct |
22 |
Correct |
3 ms |
4940 KB |
Output is correct |
23 |
Correct |
5 ms |
5324 KB |
Output is correct |
24 |
Correct |
5 ms |
5424 KB |
Output is correct |
25 |
Correct |
6 ms |
5324 KB |
Output is correct |
26 |
Correct |
7 ms |
5836 KB |
Output is correct |
27 |
Correct |
7 ms |
5844 KB |
Output is correct |
28 |
Correct |
6 ms |
5836 KB |
Output is correct |
29 |
Correct |
6 ms |
5836 KB |
Output is correct |
30 |
Correct |
5 ms |
5864 KB |
Output is correct |
31 |
Correct |
6 ms |
6220 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
4940 KB |
Output is correct |
2 |
Correct |
3 ms |
4940 KB |
Output is correct |
3 |
Correct |
3 ms |
4912 KB |
Output is correct |
4 |
Correct |
2 ms |
4940 KB |
Output is correct |
5 |
Correct |
2 ms |
4940 KB |
Output is correct |
6 |
Correct |
3 ms |
4940 KB |
Output is correct |
7 |
Correct |
3 ms |
5020 KB |
Output is correct |
8 |
Correct |
2 ms |
4940 KB |
Output is correct |
9 |
Correct |
2 ms |
4940 KB |
Output is correct |
10 |
Correct |
2 ms |
4972 KB |
Output is correct |
11 |
Correct |
2 ms |
4940 KB |
Output is correct |
12 |
Correct |
2 ms |
4940 KB |
Output is correct |
13 |
Correct |
2 ms |
4940 KB |
Output is correct |
14 |
Correct |
3 ms |
4940 KB |
Output is correct |
15 |
Correct |
3 ms |
4940 KB |
Output is correct |
16 |
Correct |
3 ms |
4940 KB |
Output is correct |
17 |
Correct |
3 ms |
4940 KB |
Output is correct |
18 |
Correct |
3 ms |
4940 KB |
Output is correct |
19 |
Correct |
3 ms |
4940 KB |
Output is correct |
20 |
Correct |
3 ms |
4940 KB |
Output is correct |
21 |
Correct |
3 ms |
4940 KB |
Output is correct |
22 |
Correct |
3 ms |
4940 KB |
Output is correct |
23 |
Correct |
5 ms |
5324 KB |
Output is correct |
24 |
Correct |
5 ms |
5424 KB |
Output is correct |
25 |
Correct |
6 ms |
5324 KB |
Output is correct |
26 |
Correct |
7 ms |
5836 KB |
Output is correct |
27 |
Correct |
7 ms |
5844 KB |
Output is correct |
28 |
Correct |
6 ms |
5836 KB |
Output is correct |
29 |
Correct |
6 ms |
5836 KB |
Output is correct |
30 |
Correct |
5 ms |
5864 KB |
Output is correct |
31 |
Correct |
6 ms |
6220 KB |
Output is correct |
32 |
Correct |
24 ms |
9124 KB |
Output is correct |
33 |
Correct |
24 ms |
9208 KB |
Output is correct |
34 |
Correct |
25 ms |
9116 KB |
Output is correct |
35 |
Correct |
145 ms |
22176 KB |
Output is correct |
36 |
Correct |
148 ms |
22212 KB |
Output is correct |
37 |
Correct |
162 ms |
22280 KB |
Output is correct |
38 |
Correct |
106 ms |
22612 KB |
Output is correct |
39 |
Correct |
99 ms |
22604 KB |
Output is correct |
40 |
Correct |
100 ms |
22524 KB |
Output is correct |
41 |
Correct |
134 ms |
26904 KB |
Output is correct |