Submission #45260

#	Time	Username	Problem	Language	Result	Execution time	Memory
45260		qoo2p5	Chase (CEOI17_chase)	C++17	70 / 100	358 ms	89404 KiB

chase

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int INF = (int) 1e9 + 1e6 + 123;
const ll LINF = (ll) 1e18 + 1e9 + 123;

#define rep(i, s, t) for (auto i = (s); i < (t); ++(i))
#define per(i, s, t) for (auto i = (s); i >= (t); --(i))
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define mp make_pair
#define pb push_back

bool mini(auto &x, const auto &y) {
	if (y < x) {
		x = y;
		return 1;
	}
	return 0;
}

bool maxi(auto &x, const auto &y) {
	if (y > x) {
		x = y;
		return 1;
	}
	return 0;
}

void run();

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	run();
	return 0;
}

const int N = (int) 1e5 + 123;
const int CNT = 101;

int n, cc;
vector<int> g[N];
ll p[N], around[N];
ll dp[N][CNT];

void dfs(int v, int f = 0) {
	rep(i, 1, cc + 1) {
		dp[v][i] = max(dp[f][i], dp[f][i - 1] + around[v] - p[f]);
	}
	for (int u : g[v]) {
		if (u == f) {
			continue;
		}
		dfs(u, v);
	}
}

void run() {
	cin >> n >> cc;
	rep(i, 1, n + 1) {
		cin >> p[i];
	}
	rep(i, 0, n - 1) {
		int a, b;
		cin >> a >> b;
		g[a].pb(b);
		g[b].pb(a);
	}
	rep(i, 1, n + 1) {
		for (int j : g[i]) {
			around[i] += p[j];
		}
	}
	
	ll ans = 0;
	
	if (n <= 1000) {
		rep(st, 1, n + 1) {
			rep(i, 1, n + 1) rep(j, 0, cc + 1) dp[i][j] = 0;
			dfs(st);
			rep(i, 1, n + 1) {
				rep(j, 1, cc + 1) {
					maxi(ans, dp[i][j]);
				}
			}
		}
	} else {
		dfs(1);
		rep(i, 1, n + 1) {
			rep(j, 1, cc + 1) {
				maxi(ans, dp[i][j]);
			}
		}
	}
	cout << ans << "\n";
}

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