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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. typedef long long int ll; 
  4. ll sum[1000];
  5. int b[1000];
  6.  
  7. void DFS(int node, vector<int> G[], int used[], int parent[]) {
  8.     used[node] = 1;
  9.     for (auto u : G[node]) {
  10.         if (used[u] == 0) {
  11.             parent[u] = node;
  12.             DFS(u, G, used, parent);
  13.         }
  14.     }
  15.  
  16.     // Bottom-up traversal
  17.     ll s = 0;
  18.     for (auto c : G[node]) {
  19.         if (c == parent[node]) {
  20.             // Ignore the parent node
  21.             continue;
  22.         } else {
  23.             s += sum[c];
  24.         }
  25.     }
  26.     sum[node] = b[node] + s; 
  27. }
  28.  
  29. int main() {
  30.     int n;
  31.     cin >> n;
  32.     vector<int> g[n + 1]; 
  33.     for (int i = 1; i <= n; i++) {
  34.         cin >> b[i]; 
  35.     }
  36.  
  37.     for (int i = 1; i <= n - 1; i++) {
  38.         int u, v;
  39.         cin >> u >> v; 
  40.         g[u].push_back(v);
  41.         g[v].push_back(u); 
  42.     }
  43.  
  44.     int used[n + 1] = {0};
  45.     int parent[n + 1] = {0};
  46.     DFS(1, g, used, parent);
  47.  
  48.     ll s = INT_MIN; 
  49.     for (int i = 1; i <= n; i++) {
  50.         s = max(s, sum[i]);
  51.     }
  52.  
  53.     cout << s; 
  54.     return 0;
  55. }
  56.  
Success #stdin #stdout 0s 5284KB
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https://ideone.com/Oop6eH
language:
C++ (gcc 8.3)
created:
7 days ago
visibility:
public

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