제출 #46500

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
46500		RockyB	Chase (CEOI17_chase)	C++17	20 / 100	4111 ms	524288 KiB

chase

/// In The Name Of God

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include <bits/stdc++.h>

#define f first
#define s second

#define pb push_back
#define pp pop_back
#define mp make_pair

#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()

#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);

#define nl '\n'
#define ioi exit(0);

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

const int N = (int)5e5 + 7;
const int inf = (int)1e9 + 7;
const int mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;

const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1};
const int dy[] = {0, 1, 0, -1, 1, -1, 1, -1};

using namespace std;

#define int ll

int n, k;
int a[N];
vector <int> g[N];

vector < vector <int> > all;
vector <int> cur;
void dfs(int v, int p = -1) {
	cur.pb(v);
	all.pb(cur);
	for (auto to : g[v]) {
		if (to != p) {
			dfs(to, v);
		}
	}
	cur.pp();
}

int rec(int v, int cnt, int x, vector <int> &cur) {
	if (v == sz(cur)) {
		int y = 0;
		for (auto it : cur) y += a[it];
		return abs(x - y);
	}

	int res = 0;
	x += a[cur[v]];
	res = max(res, rec(v + 1, cnt, x, cur));

	if (cnt < k) {
		vector <int> sve;
		int in = a[cur[v]];
		for (auto to : g[cur[v]]) {
			sve.pb(a[to]);
			a[cur[v]] += a[to];
			a[to] = 0;
		}
		res = max(res, rec(v + 1, cnt + 1, x, cur));
		for (int i = 0; i < sz(g[cur[v]]); i++) {
			a[g[cur[v]][i]] = sve[i];
		}	
		a[cur[v]] = in;
	}
	return res;
}
int32_t main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
	#endif
	Kazakhstan
	cin >> n >> k;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
	}
	for (int i = 1; i < n; i++) {
		int v, u;
		cin >> v >> u;
		g[v].pb(u);
		g[u].pb(v);
	}
	for (int i = 1; i <= n; i++) {
		dfs(i);
	}
	int ans = 0;
	for (auto it : all) {
		ans = max(ans, rec(0, 0, 0, it));
	}
	/*for (int i = 1; i <= n; i++) {
		cerr << a[i] << ' ';
	}
	cerr << nl;*/
	cout << ans;
	ioi
}

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