oj.uz

Submission #870871

# Submission time Handle Problem Language Result Execution time Memory
870871 2023-11-09T11:17:44 Z epicci23 Sjekira (COCI20_sjekira) C++17
110 / 110
 65 ms 19648 KB 
#include "bits/stdc++.h"
using namespace std;
#define pb push_back
#define endl "\n" 
#define int long long
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(),(x).end()

/* stuff you should look for
 * int overflow, array bounds
 * special cases (n=1?)
 * do smth instead of nothing and stay organized
 * WRITE STUFF DOWN
 * DON'T GET STUCK ON ONE APPROACH
 * SIMPLIFY THE PROBLEM
 * READ THE STATEMENT CAREFULLY
  !!! if there is an specified/interesting smth(i.e. constraint) in the statement,
  then you must be careful about that   
*/

const int N = 1e5 + 5;

int ar[N],par[N],ans=0;
vector<int> v[N],v2[N],vis(N,0);

int find(int a){
  if(par[a]==a) return a;
  return par[a]=find(par[a]);
}

void unite(int a,int b){
  a=find(a),b=find(b);
  if(ar[a]>ar[b]) swap(a,b);
  par[a]=b;
}

void dfs(int c,int p){
  ans += sz(v2[c]) * ar[c];
  for(int x:v2[c]){
  	if(x==p) continue;
  	dfs(x,c);
  }
}

void solve(){
  iota(par,par+N,0LL);
  int n;
  cin >> n;
  for(int i=1;i<=n;i++) cin >> ar[i];
  for(int i=1;i<n;i++){
  	int a,b;
  	cin >> a >> b;
  	v[a].pb(b);
  	v[b].pb(a);
  }
  vector<array<int,2>> xd;

  for(int i=1;i<=n;i++) xd.pb({ar[i],i});

  sort(all(xd));

  for(auto x:xd){
    int a = x[1];
    vis[a] = 1;
    for(int u : v[a]){
      if(!vis[u]) continue;
      v2[a].pb(find(u));
      v2[find(u)].pb(a);
      unite(a,u);
    }
  }

  dfs(1,0);

  cout << ans << endl;
}

int32_t main(){

  cin.tie(0); ios::sync_with_stdio(0);
  
  int t=1;//cin >> t;
  while(t--) solve();

  return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6488 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6492 KB Output is correct
5 Correct 2 ms 6492 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 43 ms 15864 KB Output is correct
2 Correct 33 ms 13684 KB Output is correct
3 Correct 31 ms 13260 KB Output is correct
4 Correct 36 ms 14264 KB Output is correct
5 Correct 65 ms 18116 KB Output is correct
6 Correct 40 ms 19648 KB Output is correct
7 Correct 35 ms 18028 KB Output is correct
8 Correct 32 ms 16836 KB Output is correct
9 Correct 21 ms 13528 KB Output is correct
10 Correct 43 ms 19356 KB Output is correct

Subtask #3
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6488 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6492 KB Output is correct
5 Correct 2 ms 6492 KB Output is correct
6 Correct 2 ms 6748 KB Output is correct
7 Correct 2 ms 6764 KB Output is correct
8 Correct 2 ms 6748 KB Output is correct
9 Correct 3 ms 6748 KB Output is correct
10 Correct 2 ms 6744 KB Output is correct

Subtask #4
60.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6488 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 2 ms 6492 KB Output is correct
5 Correct 2 ms 6492 KB Output is correct
6 Correct 43 ms 15864 KB Output is correct
7 Correct 33 ms 13684 KB Output is correct
8 Correct 31 ms 13260 KB Output is correct
9 Correct 36 ms 14264 KB Output is correct
10 Correct 65 ms 18116 KB Output is correct
11 Correct 40 ms 19648 KB Output is correct
12 Correct 35 ms 18028 KB Output is correct
13 Correct 32 ms 16836 KB Output is correct
14 Correct 21 ms 13528 KB Output is correct
15 Correct 43 ms 19356 KB Output is correct
16 Correct 2 ms 6748 KB Output is correct
17 Correct 2 ms 6764 KB Output is correct
18 Correct 2 ms 6748 KB Output is correct
19 Correct 3 ms 6748 KB Output is correct
20 Correct 2 ms 6744 KB Output is correct
21 Correct 13 ms 9436 KB Output is correct
22 Correct 13 ms 8916 KB Output is correct
23 Correct 60 ms 18120 KB Output is correct
24 Correct 50 ms 14904 KB Output is correct
25 Correct 39 ms 14788 KB Output is correct
26 Correct 25 ms 11972 KB Output is correct
27 Correct 31 ms 13016 KB Output is correct
28 Correct 49 ms 15296 KB Output is correct
29 Correct 29 ms 12492 KB Output is correct
30 Correct 63 ms 18884 KB Output is correct