Advertisement
tiom4eg

day 5, D 100

Jan 13th, 2023
477
0
Never
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
C++ 2.34 KB | None | 0 0
  1. #include <bits/stdc++.h>
  2. // tiom4eg's precompiler options
  3. // POGGERS POGGERS POGGERS POGGERS POGGERS POGGERS POGGERS
  4. // IO settings
  5. #define fastIO ios_base::sync_with_stdio(false); cin.tie(0)
  6. // Quick types
  7. #define ll long long
  8. #define ld long double
  9. #define ull unsigned long long
  10. #define pii pair <int, int>
  11. #define vi vector <int>
  12. #define mi vector <vector <int>>
  13. // Quick functions
  14. #define endl "\n"
  15. #define F first
  16. #define S second
  17. #define all(a) a.begin(), a.end()
  18. #define sz(a) (int)(a.size())
  19. #define pb push_back
  20. #define mp make_pair
  21. // Quick fors
  22. #define FOR(i, a, b) for (int i = a; i < b; ++i)
  23. #define FORS(i, a, b, c) for (int i = a; i < b; i += c)
  24. #define RFOR(i, a, b) for (int i = a; i >= b; --i)
  25. #define EACH(e, a) for (auto& e : a)
  26. // Pragmas
  27. #ifndef TIOM4EG
  28. #pragma GCC optimize("O3") // let the chaos begin!
  29. #pragma GCC target("avx,avx2,bmi,bmi2,popcnt,lzcnt,tune=native")
  30. #pragma GCC comment(linker, "/stack:200000000")
  31. #endif
  32. // PBDS
  33. #include <ext/pb_ds/assoc_container.hpp>
  34. #include <ext/pb_ds/tree_policy.hpp>
  35. #define ordered_set tree <int, null_type, less <int>, rb_tree_tag, tree_order_statistics_node_update>
  36. #define ook order_of_key
  37. #define fbo find_by_order
  38. using namespace __gnu_pbds;
  39. // POGGERS POGGERS POGGERS POGGERS POGGERS POGGERS POGGERS
  40. using namespace std;
  41. mt19937 rng(chrono::duration_cast<chrono::milliseconds>(chrono::system_clock::now().time_since_epoch()).count());
  42. #define int long long
  43. const int INF = 1e9 + 7, MD = 998244353, MAX = 100005, R = 1 << 18, MOD = 1e9 + 7, MOD2 = 1e9 + 9, MOD12 = MOD * MOD, MOD22 = MOD2 * MOD2, LG = 20, B1 = 300007, B2 = 107, B = 320;
  44. const ll INFLL = 1e18 + 7;
  45.  
  46. vector <array <int, 3>> g[MAX];
  47.  
  48. array <int, 2> dfs(int v, int p) {
  49.     int ans0 = 0, mx1 = 0, mx2 = 0, mx1d = 0;
  50.     EACH(e, g[v]) if (e[0] != p) {
  51.         auto cur = dfs(e[0], v);
  52.         if (e[2]) {
  53.             if (cur[1] + e[1] > mx1) mx2 = mx1, mx1 = cur[1] + e[1], mx1d = cur[1];
  54.             else if (cur[1] + e[1] > mx2) mx2 = cur[1] + e[1];
  55.         }
  56.         else ans0 = max(ans0, min(cur[0], cur[1] + e[1]));
  57.     }
  58.     return {max(ans0, mx1), max(ans0, max(mx1d, mx2))};
  59. }
  60.  
  61. signed main() {
  62.     fastIO;
  63.     int n; cin >> n;
  64.     FOR(i, 1, n) {
  65.         int u, v, w; cin >> u >> v >> w, --u, --v;
  66.         g[u].pb({v, w, 1}), g[v].pb({u, w, 0});
  67.     }
  68.     cout << dfs(0, 0)[1];
  69. }
  70.  
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement