제출 #392128

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
392128		soroush	Chase (CEOI17_chase)	C++17	0 / 100	1260 ms	183288 KiB

chase

//曇り空 のぞいた予感
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<ll , ll> pii;

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

const int maxn = 1e5 + 10;
const ll mod = 1e9+7;

#define pb push_back
#define endl '\n'
#define dokme(x) cout << x , exit(0)
#define ms(x , y) memset(x , y , sizeof x)
ll pw(ll a, ll b, ll md = mod){ll res = 1;while(b){if(b&1){res=(a*res)%md;}a=(a*a)%md;b>>=1;}return(res);}

int n , m , sz[maxn];
ll p[maxn];
bool hide[maxn];
vector < int > adj[maxn];
ll ans = 0;

ll dp[maxn][110] , pd[maxn][110];
void plant(int v){
	hide[v] = 1;
	sz[v] = 1;
	for(auto u : adj[v])if(!hide[u])
		plant(u) , sz[v] += sz[u];
	hide[v] = 0;
}

int cen(int v , int n , int par = 0 , bool found = 0){
	while(!found){
		found = 1;
		for(auto u : adj[v])if(!hide[u] and u ^ par and sz[u] * 2 > n){
			found = 0 , par = v , v = u;
			break;
		}
	}
	return v;
}

ll out[maxn][110] , in[maxn][110];
ll sum[maxn];


void dfs(int v , int par){
	sum[v] = 0;
	for(int i = 1 ; i <= m ; i ++)pd[v][i] = dp[v][i] = 0;
	for(auto u : adj[v])if(u^par)sum[v] += p[u];
	for(auto u : adj[v])if(!hide[u] and u ^ par){
		dfs(u , v);
		for(int i = 1 ; i <= m ; i ++){
			dp[v][i] = max(dp[v][i] , dp[u][i]);
			dp[v][i] = max(dp[v][i] , dp[u][i-1] + sum[u] - p[v]);
			pd[v][i] = max(pd[v][i] , pd[u][i]);
			pd[v][i] = max(pd[v][i] , pd[u][i-1] + sum[v] - p[u]);
		}
	}
}



void calc(int v){
	sum[v] = 0;
	for(int i = 1 ; i <= m ; i ++)pd[v][i] = dp[v][i] = 0;
	for(auto u : adj[v])sum[v] += p[u];
	for(auto u : adj[v])if(!hide[u]){
		dfs(u , v);
		for(int i = 1 ; i <= m ; i ++){
			ans = max(ans , pd[v][i] + dp[v][m-i]);
			pd[v][i] = max(pd[v][i] , pd[u][i]);
			pd[v][i] = max(pd[v][i] , pd[u][i-1] + sum[v] - p[u]);
			dp[v][i] = max(dp[v][i] , dp[u][i]);
			dp[v][i] = max(dp[v][i] , dp[u][i-1] + sum[u] - p[v]);
			ans = max(ans , dp[v][i]);
			ans = max(ans , pd[v][i]);
		}
	}
}

void solve(int v = 1){
	plant(v);
	v = cen(v , sz[v]);
	calc(v);
	hide[v] = 1;
	for(auto u : adj[v])if(!hide[u])
		solve(u);
}

int32_t main(){
	ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	cin >> n >> m;
	for(int i = 1 ; i <= n ; i ++)
		cin >> p[i];
	for(int i = 1 ; i < n ; i ++){
		int u , v;
		cin >> u >> v;
		sum[v] += p[u];sum[u] += p[v];
		adj[u].pb(v);
		adj[v].pb(u);
	}
	solve();
	cout << ans;
	return(0);
}

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