#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define in insert
#define all(x) x.begin(),x.end()
#define pb push_back
#define eb emplace_back
#define ff first
#define ss second
#define int long long
typedef long long ll;
typedef vector<int> vi;
typedef set<int> si;
typedef multiset<int> msi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
template<typename T, typename U>
ostream & operator << (ostream &out, const pair<T, U> &c) {
out << c.first << ' ' << c.second;
return out;
}
template<typename T>
ostream & operator << (ostream &out, vector<T> &v) {
const int sz = v.size();
for (int i = 0; i < sz; i++) {
if (i) out << ' ';
out << v[i];
}
return out;
}
template<typename T>
istream & operator >> (istream &in, vector<T> &v) {
for (T &x : v) in >> x;
return in;
}
template<typename T>
void mxx(T &a, T b){if(b > a) a = b;}
template<typename T>
void mnn(T &a, T b){if(b < a) a = b;}
const int mxn = 2e5 + 10, inf = 1e18;
int n, f[mxn], g[mxn], ans;
vector<pair<int, int>> adj[mxn];
void dfs1(int to, int fr) {
f[to] = 0;
g[to] = -inf;
int mx1 = -inf;
for(auto it : adj[to]) {
if(it.ff == fr) continue;
int x = it.ff;
dfs1(x, to);
f[to] += max(f[x], g[x] + it.ss);
mxx(mx1, f[x] + it.ss - max(f[x], g[x] + it.ss));
}
mxx(g[to], f[to] + mx1);
}
void go() {
cin >> n;
for(int i = 1; i < n; i++) {
int x, y, c;
cin >> x >> y >> c;
adj[x].eb(y, c);
adj[y].eb(x, c);
}
for(int i = 1; i <= n; i++) {
dfs1(i, 0);
mxx(ans, f[i]);
}
cout << ans << '\n';
}
signed main() {
#ifndef ONO
freopen("beads.in", "r", stdin);
freopen("beads.out", "w", stdout);
#endif
fast;
int t = 1;
// cin >> t;
while(t--) {
go();
}
return 0;
}
Compilation message
beads.cpp: In function 'int main()':
beads.cpp:84:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
84 | freopen("beads.in", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
beads.cpp:85:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
85 | freopen("beads.out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
5076 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
5076 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
5076 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
5076 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
