제출 #392103

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
392103		sinamhdv	Chase (CEOI17_chase)	C++11	100 / 100	348 ms	230684 KiB

chase

// CEOI17_chase
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 1000 * 1000 * 1000 + 7;
const int INF = 1e9 + 100;
const ll LINF = 1e18 + 100;

#ifdef DEBUG
#define dbg(x) cout << #x << " = " << (x) << endl << flush;
#define dbgr(s, f) { cout << #s << ": "; for (auto _ = (s); _ != (f); _++) cout << *_ << ' '; cout << endl << flush; }
#else
#define dbg(x) ;
#define dbgr(s, f) ;
#endif
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define fast_io ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define mp make_pair
#define fr first
#define sc second
#define endl '\n'

#define MAXN 100100
#define MAXB 110

int n, B;
int p[MAXN];
ll a[MAXN];
vector<int> adj[MAXN];

ll ans = 0;
ll up[MAXN][MAXB];
ll dn[MAXN][MAXB];

void dfs(int v, int par)
{
	FOR(k, 1, B + 1)
		up[v][k] = a[v];

	for (int u : adj[v])
	{
		if (u == par) continue;
		dfs(u, v);
		
		ll udp[MAXB] = {}, ddp[MAXB] = {};

		FOR(k, 1, B + 1)
		{
			udp[k] = max(up[u][k], up[u][k - 1] + a[v] - p[u]);
			ddp[k] = max(dn[u][k], dn[u][k - 1] + a[u] - p[v]);
		}

		FOR(k, 0, B + 1)
			ans = max({ans, dn[v][k] + udp[B - k], up[v][k] + ddp[B - k]});

		FOR(k, 1, B + 1)
		{
			up[v][k] = max(up[v][k], udp[k]);
			dn[v][k] = max(dn[v][k], ddp[k]);
		}
	}
}

int32_t main(void)
{
	fast_io;
	cin >> n >> B;
	FOR(i, 1, n + 1) cin >> p[i];
	FOR(i, 1, n)
	{
		int x, y;
		cin >> x >> y;
		adj[x].pb(y);
		adj[y].pb(x);
		a[x] += p[y];
		a[y] += p[x];
	}

	if (B == 0) return cout << "0\n", 0;

	dfs(1, -1);

	cout << ans << endl;
	
	return 0;
}

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