제출 #583295

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
583295		600Mihnea	Chase (CEOI17_chase)	C++17	40 / 100	4097 ms	263760 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]);
      }
    }
  }
}

/// sol = max(sol, sum_vecs[a]);

void dfs3(int a, int p = 0) {
  for (auto &b : g[a]) {
    if (b != p) {
      dfs3(b, a);
    }
  }
  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 : g[a]) {
    if (b == p) {
      continue;
    }
    for (auto &c : g[a]) {
      if (c == p) {
        continue;
      }
      if (b == c) {
        continue;
      }
      /// no a
      for (int i = 0; i <= bread_have; i++) {
        sol = max(sol, dp1[b][i] + dp2[c][bread_have - i]);

      }
      /// yes a
      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);

  ///freopen ("input.txt", "r", stdin);

  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;
  }
  ll Max = 0;
  for (int root = 1; root <= n; root++) {
    root = 1;
    for (int i = 0; i <= n + 1; i++) {
      for (int j = 0; j <= bread_have + 1; j++) {
        dp1[i][j] = 0;
        dp2[i][j] = 0;
        dp3[i][j] = 0;
      }
    }
    sol = -INF;
    dfs1(root);
    dfs2(root);
    dfs3(root);
    cout << sol << "\n";
    exit(0);
    cout << root << " ---> " << sol << "\n";
    Max = max(Max, sol);

    //exit(0);
  }

  cout << "\t\t\t\t Max = " << Max << "\n";

  assert(Max <= 36);

  return 0;


  /*ll sol = -INF;
  for (int root = 1; root <= n; root++) {
    dfs_down(root);
    dfs_up(root);
   /// sol = max(sol, from_up[root][bread_have]);


    exit(0);
  }
  cout << sol << "\n";*/
}

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