Submission #210122

#	Time	Username	Problem	Language	Result	Execution time	Memory
210122		casperwang	Paprike (COI18_paprike)	C++14	13 / 100	77 ms	6652 KiB

paprike

#include <bits/stdc++.h>
#define pb push_back
#define pii pair<int,int>
#define ff first
#define ss second
using namespace std;

const int MAXN = 100000;
int n, k;
int a, b;
int cnt;
int v[MAXN+1];
int deg[MAXN+1];
bool vis[MAXN+1];
vector <int> path[MAXN+1];
priority_queue <pii,vector <pii>,greater<pii>> nxt;

void DFS(int now, int par) {
  vis[now] = 1;
  for (int i : path[now]) {
    if (vis[i] || i == par) continue;
    if (v[now] + v[i] > k) cnt++;
    else v[i] += v[now];
    deg[i]--;
    if (deg[i] == 1) DFS(i, now);
  }
}

signed main() {
  ios_base::sync_with_stdio(0), cin.tie(0);
  cin >> n >> k;
  for (int i = 1; i <= n; i++)
    cin >> v[i];
  for (int i = 1; i < n; i++) {
    cin >> a >> b;
    path[a].pb(b), deg[a]++;
    path[b].pb(a), deg[b]++;
  }
  for (int i = 1; i <= n; i++)
    if (deg[i] == 1)
      nxt.push(pii(v[i], i));
  while (nxt.size()) {
    int now = nxt.top().ss;
    nxt.pop(), vis[now] = 1;
    for (int i : path[now]) {
      if (vis[i]) continue;
      if (v[now] + v[i] > k) cnt++;
      else v[i] += v[now];
      deg[i]--;
      if (deg[i] == 1)
        nxt.push(pii(v[i], i));
    }
  }
  cout << cnt << "\n";
}

• Subtask 1: 0 / 11
• Subtask 2: 13 / 13
• Subtask 3: 0 / 27
• Subtask 4: 0 / 49