제출 #583298

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
583298		600Mihnea	Chase (CEOI17_chase)	C++17	40 / 100	4085 ms	181728 KiB

chase

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const int N = (int) 1e5 + 7;
const int B = 100 + 7;
const ll INF = (ll) 1e18 + 7;
int n, bread_have, pigs[N];
vector<int> g[N];
ll sum_vecs[N];
ll dp1[N][B];
ll dp2[N][B];
ll dp3[N][B];
ll sol;

void dfs1(int a, int p = 0) {
  for (auto &b : g[a]) {
    if (b != p) {
      dfs1(b, a);
    }
  }
  for (int i = 0; i <= bread_have; i++) {
    if (i >= 1) {
      dp1[a][i] = max(dp1[a][i], sum_vecs[a]);
    }
  }
  for (auto &b : g[a]) {
    if (b == p) {
      continue;
    }
    for (int i = 0; i <= bread_have; i++) {
      dp1[a][i] = max(dp1[a][i], dp1[b][i]);
      if (i >= 1) {
        dp1[a][i] = max(dp1[a][i], dp1[b][i - 1] + (sum_vecs[a] - pigs[b]));
      }
    }
  }
}

void dfs2(int a, int p = 0) {
  for (auto &b : g[a]) {
    if (b != p) {
      dfs2(b, a);
    }
  }
  for (auto &b : g[a]) {
    if (b == p) {
      continue;
    }
    for (int i = 0; i <= bread_have; i++) {
      dp2[a][i] = max(dp2[a][i], dp2[b][i]);
      if (i >= 1) {
        dp2[a][i] = max(dp2[a][i], dp2[b][i - 1] + (sum_vecs[a] - pigs[p]));
      }
    }
  }
  for (auto &b : g[a]) {
    if (b == p) {
      continue;
    }
    for (int i = 0; i <= bread_have; i++) {
      dp3[a][i] = max(dp3[a][i], dp2[b][i]);
      if (i >= 1) {
        dp3[a][i] = max(dp3[a][i], dp2[b][i - 1] + sum_vecs[a]);
      }
    }
  }
}


void dfs3(int a, int p = 0) {
  vector<int> Kids;
  for (auto &b : g[a]) {
    if (b != p) {
      dfs3(b, a);
      Kids.push_back(b);
    }
  }
  g[a] = Kids;
  sol = max(sol, sum_vecs[a]);
  sol = max(sol, dp1[a][bread_have]);
  sol = max(sol, dp2[a][bread_have]);
  sol = max(sol, dp3[a][bread_have]);


  for (auto &b : Kids) {
    for (auto &c : Kids) {
      if (b == c) {
        continue;
      }
      for (int i = 0; i <= bread_have; i++) {
        sol = max(sol, dp1[b][i] + dp2[c][bread_have - i]);
      }
      for (int i = 0; i + 1 <= bread_have; i++) {
        sol = max(sol, dp1[b][i] + dp2[c][bread_have - i - 1] + (sum_vecs[a] - pigs[b]));
      }
    }
  }
}

signed main() {
  ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

  cin >> n >> bread_have;

  for (int i = 1; i <= n; i++) {
    cin >> pigs[i];
  }

  for (int i = 1; i < n; i++) {
    int a, b;
    cin >> a >> b;
    g[a].push_back(b);
    g[b].push_back(a);
    sum_vecs[a] += pigs[b];
    sum_vecs[b] += pigs[a];
  }
  if (bread_have == 0) {
    cout << "0\n";
    return 0;
  }
  dfs1(1);
  dfs2(1);
  dfs3(1);
  cout << sol << "\n";

}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 30