#include <bits/stdc++.h>
#pragma GCC Optimize("O3")
#define FOR(i, x, y) for (ll i = x; i < y; i++)
#define MOD 1000000007
typedef long long ll;
using namespace std;
vector<pair<ll, ll>> graph[200001];
ll dp1[200001], dp2[200001];
void dfs(ll node, ll parent, ll edge) {
ll best = INT_MIN, second = INT_MIN;
for (pair<ll, ll> i : graph[node]) {
if (i.first != parent) {
dfs(i.first, node, i.second);
dp1[node] += max(dp1[i.first], dp2[i.first]);
}
}
for (pair<ll, ll> i : graph[node]) {
if (i.first != parent) {
dp2[node] = max(dp2[node], dp1[node] - max(dp1[i.first], dp2[i.first]) + dp1[i.first] + i.second + edge);
if (dp1[i.first] + i.second - max(dp1[i.first], dp2[i.first]) > best) {
second = best;
best = dp1[i.first] + i.second - max(dp1[i.first], dp2[i.first]);
} else if (dp1[i.first] + i.second - max(dp1[i.first], dp2[i.first]) > second) {
second = dp1[i.first] + i.second - max(dp1[i.first], dp2[i.first]);
}
}
}
if (best + second > 0) dp1[node] += best + second;
}
int main() {
iostream::sync_with_stdio(false);
cin.tie(0);
ll n;
cin >> n;
FOR(i, 1, n) {
ll a, b, c;
cin >> a >> b >> c;
graph[a].push_back({b, c});
graph[b].push_back({a, c});
}
dfs(1, 0, 0);
cout << dp1[1] << '\n';
return 0;
}
Compilation message
beads.cpp:2:0: warning: ignoring #pragma GCC Optimize [-Wunknown-pragmas]
#pragma GCC Optimize("O3")
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
5032 KB |
Output is correct |
2 |
Correct |
6 ms |
4984 KB |
Output is correct |
3 |
Correct |
6 ms |
4984 KB |
Output is correct |
4 |
Correct |
6 ms |
5028 KB |
Output is correct |
5 |
Correct |
6 ms |
5112 KB |
Output is correct |
6 |
Incorrect |
6 ms |
4984 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
5032 KB |
Output is correct |
2 |
Correct |
6 ms |
4984 KB |
Output is correct |
3 |
Correct |
6 ms |
4984 KB |
Output is correct |
4 |
Correct |
6 ms |
5028 KB |
Output is correct |
5 |
Correct |
6 ms |
5112 KB |
Output is correct |
6 |
Incorrect |
6 ms |
4984 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
5032 KB |
Output is correct |
2 |
Correct |
6 ms |
4984 KB |
Output is correct |
3 |
Correct |
6 ms |
4984 KB |
Output is correct |
4 |
Correct |
6 ms |
5028 KB |
Output is correct |
5 |
Correct |
6 ms |
5112 KB |
Output is correct |
6 |
Incorrect |
6 ms |
4984 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
5032 KB |
Output is correct |
2 |
Correct |
6 ms |
4984 KB |
Output is correct |
3 |
Correct |
6 ms |
4984 KB |
Output is correct |
4 |
Correct |
6 ms |
5028 KB |
Output is correct |
5 |
Correct |
6 ms |
5112 KB |
Output is correct |
6 |
Incorrect |
6 ms |
4984 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |