Submission #199821

#	Time	Username	Problem	Language	Result	Execution time	Memory
199821		quocnguyen1012	Magic Tree (CEOI19_magictree)	C++14	100 / 100	195 ms	37112 KiB

magictree

#include <bits/stdc++.h>

#define fi first
#define se second
#define mp make_pair
#define pb push_back

using namespace std;
typedef long long ll;

const int maxn = 1e5 + 5;

vector<int> adj[maxn];
map<int, ll> f[maxn];
int N, W[maxn], D[maxn], M, K;

void dfs(int u)
{
  for (int v : adj[u]){
    dfs(v);
    if (f[v].size() > f[u].size()) swap(f[u], f[v]);
    for (auto & all : f[v])
      f[u][all.fi] += all.se;
  }
  if (D[u]){
    vector<int> vi;
    ll sum = 0;
    auto it = f[u].upper_bound(D[u]);
    for (; it != f[u].end(); ++it){
      sum += it->se;
      if (W[u] < sum) break;
      vi.pb(it->fi);
    }
    if (it != f[u].end()) it->se = sum - W[u];
    for (auto & i : vi) f[u].erase(i);
    f[u][D[u]] += W[u];
  }
}

signed main(void)
{
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  if (fopen("A.INP", "r")){
    freopen("A.INP", "r", stdin);
    freopen("A.OUT", "w", stdout);
  }
  cin >> N >> M >> K;
  for (int i = 2; i <= N; ++i){
    int p; cin >> p;
    adj[p].pb(i);
  }
  for (int i = 1; i <= M; ++i){
    int u; cin >> u;
    cin >> D[u] >> W[u];
  }
  dfs(1);
  ll ret = 0;
  for (auto it : f[1]) ret += it.se;
  cout << ret;
}

Compilation message (stderr)

magictree.cpp: In function 'int main()':
magictree.cpp:44:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen("A.INP", "r", stdin);
     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
magictree.cpp:45:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen("A.OUT", "w", stdout);
     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 3 / 3
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12
• Subtask 5: 16 / 16
• Subtask 6: 13 / 13
• Subtask 7: 22 / 22
• Subtask 8: 17 / 17