제출 #525164

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
525164		Yazan_Alattar	Chase (CEOI17_chase)	C++14	100 / 100	529 ms	506864 KiB

chase

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 100007;
const ll inf = 1e9;
const ll mod = 998244353;
const double pi = acos(-1);
const int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};

vector <int> adj[M];
pair <ll,ll> mx[M][105][2];
int n, v, a[M], who[M][105][2];
ll dp[M][105], ans;

void dfs(int node, int p)
{
	ll sum = 0;
	for(auto i : adj[node]) if(i != p) sum += a[i];
	for(auto i : adj[node]) if(i != p){
		dfs(i, node);
		for(int j = 1; j <= v; ++j) dp[node][j] = max(dp[node][j], max(dp[i][j], dp[i][j - 1] + sum));
	}
	return;
}

void reroot(int node, int p)
{
	ll sum = 0;
	for(auto i : adj[node]) sum += a[i];
	for(auto i : adj[node])	for(int j = 1; j <= v; ++j) dp[node][j] = max(dp[node][j], max(dp[i][j], dp[i][j - 1] + sum));
		
	ans = max(ans, dp[node][v]);
	
	for(auto i : adj[node]){
		for(int j = 1; j <= v; ++j){
			for(int k = 0; k < 2; ++k){
				if(dp[i][j - k] > mx[node][j][k].F){
					mx[node][j][k].S = mx[node][j][k].F;
					mx[node][j][k].F = dp[i][j - k];
					who[node][j][k] = i;
				}
				else if(dp[i][j - k] > mx[node][j][k].S) mx[node][j][k].S = dp[i][j - k];
			}
		}
	}
	
	for(auto i : adj[node]) if(i != p){
		for(int j = 1; j <= v; ++j){
			ll x[2] = {0};
			for(int k = 0; k < 2; ++k){
				if(who[node][j][k] == i) x[k] = mx[node][j][k].S;
				else x[k] = mx[node][j][k].F;
			}
			dp[node][j] = max(x[0], x[1] + sum - a[i]);
		}
		reroot(i, node);
	}
	return;
}

int main()
{
	scanf("%d%d", &n, &v);
	for(int i = 1; i <= n; ++i) scanf("%d", &a[i]);
	for(int i = 1; i < n; ++i){
		int x, y;
		scanf("%d%d", &x, &y);
		adj[x].pb(y);
		adj[y].pb(x);
	}
	dfs(1, 0);
	reroot(1, 0);
	printf("%lld\n", ans);
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

chase.cpp: In function 'int main()':
chase.cpp:68:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |  scanf("%d%d", &n, &v);
      |  ~~~~~^~~~~~~~~~~~~~~~
chase.cpp:69:35: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |  for(int i = 1; i <= n; ++i) scanf("%d", &a[i]);
      |                              ~~~~~^~~~~~~~~~~~~
chase.cpp:72:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |   scanf("%d%d", &x, &y);
      |   ~~~~~^~~~~~~~~~~~~~~~

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