Submission #870383

#	Time	Username	Problem	Language	Result	Execution time	Memory
870383		fanwen	Chase (CEOI17_chase)	C++17	100 / 100	188 ms	161876 KiB

chase

#include <bits/stdc++.h>

using namespace std;

#define MASK(x) (1LL << (x))
#define BIT(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end()
#define REP(i, n) for (int i = 0, _n = n; i < _n; ++i)
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define FORE(i, a, b) for (int i = (a), _b = (b); i < _b; ++i)
#define debug(...) "[" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }

template <class A, class B> bool minimize(A &a, B b)  { if (a > b) { a = b; return true; } return false; }
template <class A, class B> bool maximize(A &a, B b)  { if (a < b) { a = b; return true; } return false; }
template <class T> T max(T a, T b, T c) { return max(a, max(b, c)); }

const int MAX = 1e5 + 5;

int N, K, p[MAX];
long long ans, sum_adj[MAX], up[MAX][105], down[MAX][105];
vector <int> adj[MAX];

void dfs(int u, int pa) {
    up[u][1] = sum_adj[u];
    for (auto v : adj[u]) if(v != pa) {
        dfs(v, u);
        FOR(i, 1, K) ans = max(ans, up[u][i] + down[v][K - i]);
        FOR(i, 1, K) {
            down[u][i] = max(down[u][i], down[v][i], down[v][i - 1] + sum_adj[u] - p[pa]);
            up[u][i] = max(up[u][i], up[v][i], up[v][i - 1] + sum_adj[u]- p[v]);
        }
    }

    memset(up[u], 0, sizeof up[u]);
    up[u][1] = sum_adj[u];

    reverse(adj[u].begin(), adj[u].end());

    for (auto v : adj[u]) if(v != pa) {
        FOR(i, 1, K) ans = max(ans, up[u][i] + down[v][K - i]);
        FOR(i, 1, K) {
            down[u][i] = max(down[u][i], down[v][i], down[v][i - 1] + sum_adj[u] - p[pa]);
            up[u][i] = max(up[u][i], up[v][i], up[v][i - 1] + sum_adj[u]- p[v]);
        }
    } 
}

void you_make_it(void) {
    cin >> N >> K;
    FOR(i, 1, N) cin >> p[i];
    FORE(i, 1, N) {
        int u, v; cin >> u >> v;
        adj[u].emplace_back(v);
        adj[v].emplace_back(u);
        sum_adj[u] += p[v], sum_adj[v] += p[u];
    }
    dfs(1, 0);
    cout << ans;
}

signed main() {

#ifdef LOCAL
    freopen("TASK.inp", "r", stdin);
    freopen("TASK.out", "w", stdout);
#endif
    file("ceoi17_chase");
    auto start_time = chrono::steady_clock::now();

    cin.tie(0), cout.tie(0) -> sync_with_stdio(0);

    you_make_it();

    auto end_time = chrono::steady_clock::now();

    cerr << "\nExecution time : " << chrono::duration_cast <chrono::milliseconds> (end_time - start_time).count() << "[ms]" << endl;

    return (0 ^ 0);
}

// Dream it. Wish it. Do it.

Compilation message (stderr)

chase.cpp: In function 'int main()':
chase.cpp:13:57: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 | #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
chase.cpp:69:5: note: in expansion of macro 'file'
   69 |     file("ceoi17_chase");
      |     ^~~~
chase.cpp:13:90: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 | #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
chase.cpp:69:5: note: in expansion of macro 'file'
   69 |     file("ceoi17_chase");
      |     ^~~~

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