제출 #645605

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
645605		tth37	Chase (CEOI17_chase)	C++14	0 / 100	297 ms	260160 KiB

chase

#include <iostream>
#include <vector>

const int N = 1e5 + 5;
const int M = 100 + 5;
const long long INF = 1e18;

using pll = std::pair<long long, long long>;

int n, m;
std::vector<int> G[N];

long long a[N], sum[N], f[N][M], sum_u, f_u[M], ans = -INF;
pll mx[N][M], mx_u[M];

void update_mx(pll &cur, long long val) {
  if (val > cur.first) {
    cur.second = cur.first;
    cur.first = val;
  } else if (val > cur.second) {
    cur.second = val;
  }
}

void remove_mx(pll &cur, long long val) {
  if (cur.first == val) {
    cur.first = cur.second;
    cur.second = -INF;
  } else if (cur.second == val) {
    cur.second = -INF;
  }
}

void dfs1(int u, int fa) {
  for (int i = 1; i <= m; ++i)
    mx[u][i] = {-INF, -INF};
  for (auto v : G[u]) {
    if (v == fa)
      continue;
    dfs1(v, u);
    sum[u] += a[v];
    for (int i = 1; i <= m; ++i) {
      update_mx(mx[u][i], -a[v] + f[v][i - 1]);
    }
  }
  f[u][0] = a[u] + sum[u];
  for (int i = 1; i <= m; ++i) {
    f[u][i] = a[u] + sum[u] + mx[u][i].first;
  }
}

void dfs2(int u, int fa) {
  for (auto v : G[u]) {
    if (v == fa)
      continue;
    // h'[u]
    sum_u = sum[u] - a[v];
    for (int i = 1; i <= m; ++i) {
      mx_u[i] = mx[u][i];
      remove_mx(mx_u[i], -a[v] + f[v][i - 1]);
    }
    // f'[u]
    f_u[0] = a[u] + sum_u;
    for (int i = 1; i <= m; ++i) {
      f_u[i] = a[u] + sum_u + mx_u[i].first;
    }
    // h[v]
    sum[v] += a[u];
    for (int i = 1; i <= m; ++i) {
      update_mx(mx[v][i], -a[u] + f_u[i - 1]);
    }
    // f[v]
    f[v][0] = a[v] + sum[v];
    for (int i = 1; i <= m; ++i) {
      f[v][i] = a[v] + sum[v] + mx[v][i].first;
    }
    dfs2(v, u);
  }
}

int main() {
  scanf("%d%d", &n, &m);
  if (m == 0) {
    puts("0");
    return 0;
  }
  for (int i = 1; i <= n; ++i)
    scanf("%lld", &a[i]);
  for (int i = 1; i < n; ++i) {
    int u, v;
    scanf("%d%d", &u, &v);
    G[u].push_back(v), G[v].push_back(u);
  }
  dfs1(1, 0);
  dfs2(1, 0);
  for (int u = 1; u <= n; ++u) {
    long long cur = -INF;
    for (int i = 0; i <= m - 1; ++i)
      cur = std::max(cur, f[u][i]);
    ans = std::max(ans, cur - a[u]);
  }
  // for (int i = 1; i <= n; ++i)
  //   std::cout << f[i][0] << " ";
  printf("%lld", ans);
  return 0;
}

/*
12 2
2 3 3 8 1 5 6 7 8 3 5 4
2 1
2 7
3 4
4 7
7 6
5 6
6 8
6 9
7 10
10 11
10 12
*/

컴파일 시 표준 에러 (stderr) 메시지

chase.cpp: In function 'int main()':
chase.cpp:82:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |   scanf("%d%d", &n, &m);
      |   ~~~~~^~~~~~~~~~~~~~~~
chase.cpp:88:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |     scanf("%lld", &a[i]);
      |     ~~~~~^~~~~~~~~~~~~~~
chase.cpp:91:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |     scanf("%d%d", &u, &v);
      |     ~~~~~^~~~~~~~~~~~~~~~

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