Submission #565310

#	Time	Username	Problem	Language	Result	Execution time	Memory
565310		SSRS	Election Campaign (JOI15_election_campaign)	C++14	20 / 100	524 ms	262144 KiB

election_campaign

#include <bits/stdc++.h>
using namespace std;
int main(){
  int N;
  cin >> N;
  vector<vector<int>> E(N);
  for (int i = 0; i < N - 1; i++){
    int X, Y;
    cin >> X >> Y;
    X--;
    Y--;
    E[X].push_back(Y);
    E[Y].push_back(X);
  }
  int M;
  cin >> M;
  vector<int> A(M), B(M), C(M);
  for (int i = 0; i < M; i++){
    cin >> A[i] >> B[i] >> C[i];
    A[i]--;
    B[i]--;
  }
  vector<int> p(N, -1);
  vector<vector<int>> c(N);
  vector<int> d(N, 0);
  queue<int> Q;
  Q.push(0);
  vector<int> bfs;
  while (!Q.empty()){
    int v = Q.front();
    Q.pop();
    bfs.push_back(v);
    for (int w : E[v]){
      if (w != p[v]){
        p[w] = v;
        c[v].push_back(w);
        d[w] = d[v] + 1;
        Q.push(w);
      }
    }
  }
  vector<vector<int>> path(M);
  vector<vector<int>> id(N);
  for (int i = 0; i < M; i++){
    int u = A[i], v = B[i];
    while (d[u] > d[v]){
      path[i].push_back(u);
      u = p[u];
    }
    while (d[v] > d[u]){
      path[i].push_back(v);
      v = p[v];
    }
    while (u != v){
      path[i].push_back(u);
      path[i].push_back(v);
      u = p[u];
      v = p[v];
    }
    path[i].push_back(u);
    id[u].push_back(i);
  }
  reverse(bfs.begin(), bfs.end());
  vector<int> dp(N, 0);
  vector<int> dpsum(N, 0);
  for (int v : bfs){
    for (int w : c[v]){
      dpsum[v] += dp[w];
    }
    int tmp = dpsum[v];
    for (int w : id[v]){
      vector<bool> in_path(N, false);
      int sum = 0;
      for (int x : path[w]){
        sum += dpsum[x] - dp[x];
      }
      tmp = max(tmp, sum + C[w]);
    }
    dp[v] = tmp;
  }
  cout << dp[0] << endl;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 5
• Subtask 3: 0 / 5
• Subtask 4: 0 / 30
• Subtask 5: 10 / 10
• Subtask 6: 0 / 40