Submission #571751

#	Time	Username	Problem	Language	Result	Execution time	Memory
571751		piOOE	Chase (CEOI17_chase)	C++17	0 / 100	4051 ms	11912 KiB

chase

#include <bits/stdc++.h>

using namespace std;

#define sz(x) ((int)size(x))
#define all(x) begin(x), end(x)
#define trace(x) cout << #x << ": " << (x) << endl;

typedef long long ll;

mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

int rand(int l, int r) { return (int) ((ll) rnd() % (r - l + 1)) + l; }

const int N = 100001;

vector<int> g[N];
int n, k, parent[N], depth[N];
ll p[N], pp[N];

void dfs(int v) {
    for (int to: g[v]) {
        if (to != parent[v]) {
            parent[to] = v;
            depth[to] = depth[v] + 1;
            dfs(to);
        }
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> k;
    for (int i = 0; i < n; ++i) {
        cin >> p[i];
    }
    for (int i = 1; i < n; ++i) {
        int a, b;
        cin >> a >> b;
        --a, --b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    ll ans = 0;
    for (int r = 0; r < n; ++r) {
        parent[r] = -1;
        depth[r] = 1;
        dfs(r);
        for (int v = 0; v < n; ++v) {
            vector<int> now;
            {
                int x = v;
                while (x != -1) {
                    now.push_back(x);
                    x = parent[x];
                }
            }
            assert(sz(now) == depth[v]);
            for (int mask = 0; mask < (1 << depth[v]); ++mask) {
                if (__builtin_popcount(mask) <= k) {
                    ll jerry = 0, tom = 0;
                    memcpy(pp, p, sizeof(pp[0]) * n);
                    for (int i = 0; i < sz(now); ++i) {
                        jerry += pp[now[i]];
                        if (mask & 1 << k) {
                            for (int to: g[now[i]]) {
                                pp[now[i]] += pp[to];
                                pp[to] = 0;
                            }
                        }
                    }
                    for (int x : now)
                        tom += pp[x];
                    ans = max(ans, tom - jerry);
                }
            }
        }
    }
    cout << ans;
    return 0;
}

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