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  1. #include <bits/stdc++.h>
  2. #define FAST ios_base::sync_with_stdio(false);cin.tie();cout.tie();
  3. #define FILE_READ_IN freopen("input.txt","r",stdin);
  4. #define FILE_READ_OUT freopen("output.txt","w",stdout);
  5. using namespace std;
  6. typedef long long ll;
  7. vector<vector<int>> adj;
  8. vector<bool> vis;
  9. bool ans=true;
  10. ll dfs(int v,ll *p,ll *h,ll *B,int parent=-1){
  11. 	vis[v]=true;
  12. 	ll sum=0,total=p[v];
  13. 	for(int u:adj[v]){
  14. 		if(!vis[u]){
  15. 			total+=dfs(u,p,h,B,v);
  16. 			sum+=B[u];
  17. 		}
  18. 	}
  19. 	if((total-h[v])%2!=0) ans=false;
  20. 	B[v]=(total-h[v])/2;
  21. 	if(B[v]<0||B[v]>total) ans=false;
  22. 	if(sum<B[v]) ans=false;
  23.  
  24. 	return total;
  25. }
  26.  
  27. int main()
  28. {
  29. 	int t; cin>>t;
  30. 	while(t--){
  31. 		ans=false;
  32. 		int n; cin>>n;
  33. 		adj.resize(n); vis.resize(n,false);
  34. 		ll m; cin>>m;
  35. 		ll p[n],h[n];
  36. 		for (int i = 0; i < n; i++)
  37. 		{
  38. 			cin>>p[i];
  39. 		}
  40. 		for (int i = 0; i < n; i++)
  41. 		{
  42. 			cin>>h[i];
  43. 		}
  44. 		for(int i=0;i<n-1;i++){
  45. 			int u,v; cin>>u>>v; u--,v--;
  46. 			adj[u].push_back(v);
  47. 			adj[v].push_back(u);
  48. 		}
  49. 		ll B[n];
  50. 		dfs(0,p,h,B);
  51. 		if(ans) cout<<"YES\n";
  52. 		else cout<<"NO\n";
  53. 		adj.clear();
  54. 		vis.clear();
  55. 	}
  56. }
  57.  
  58.  
  59.  
Runtime error #stdin #stdout 0s 4288KB
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Standard input is empty
stdout
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Standard output is empty
https://ideone.com/x1fXgM
language:
C++14 (clang 8.0)
created:
3 years ago
visibility:
public

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