Submission #571736

#	Time	Username	Problem	Language	Result	Execution time	Memory
571736		piOOE	Chase (CEOI17_chase)	C++17	0 / 100	4061 ms	11240 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] = r;
        depth[r] = 1;
        dfs(r);
        for (int v = 0; v < n; ++v) {
            if (depth[v] <= k) {
                memcpy(pp, p, sizeof(pp[0]) * n);
                ll cntnow = 0, cntnext = 0;
                int x = v;
                while (x != r) {
                    cntnow += pp[x];
                    for (int to: g[x]) {
                        pp[x] += pp[to];
                        pp[to] = 0;
                    }
                    x = parent[x];
                }
                {
                    cntnow += pp[x];
                    for (int to: g[x]) {
                        pp[x] += pp[to];
                        pp[to] = 0;
                    }
                }
                {
                    x = v;
                    while (x != r) {
                        cntnext += pp[x];
                        x = parent[x];
                    }
                    cntnext += pp[r];
                }
                ans = max(ans, cntnext - cntnow);
            }
        }
    }
    cout << ans;
    return 0;
}

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