oj.uz

답안 #122506

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
122506 2019-06-28T13:24:43 Z sams Chase (CEOI17_chase) C++14
100 / 100
 810 ms 254960 KB 
/*
  CEOI 2017 - Task Chase
  Solving by Samyra Almeida
  
  With a dfs we do the dp[u][i] = the biggest difference between the children of x, the number of pigeons that are seen by Tom and Jerry 
  from the root (first statue of the way) to the u statue, still having i crumbs and dp2[u][i] = the second biggest difference, 
  from a child other than u, to the number of pigeons that are seen by Tom and Jerry from the root (first statue of the path) to 
  the x statue, still having i crumbs.
  
  
*/

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
const int maxn = 1e5+10, maxk = 110;
 
int n, k;
ll dp[maxn][maxk], dp2[maxn][maxk], ant[maxn][maxk], ans, vis[maxn], vet[maxn];
 
vector <int> graph[maxn];
 
void dfs(int u, int f = 0)
{
	for(int v: graph[u])
	{	
		if(v == f) continue;
		dfs(v, u);
 
		for(int i = 1 ; i <= k ; ++i)
		{
			ll val = max(dp[v][i-1] + vis[v] - vet[u], dp[v][i]);
		
			if(val > dp[u][i]) dp2[u][i] = dp[u][i], dp[u][i] = val;
			else if(val > dp2[u][i]) dp2[u][i] = val;
		}
	}
}
 
void rotate(int u, int f = 0)
{
	for(int i = 1 ; i <= k ; ++i)
	{
		ans = max({ans, dp[u][i], dp[u][i-1] + vis[u]});
	}
 
	for(int v: graph[u])
	{
		if(v == f) continue;
 
		for(int i = 1 ; i <= k ; ++i)
		{
			ant[u][i] = dp[u][i];
			
			ll val = max(dp[v][i], dp[v][i-1] + vis[v] - vet[u]);
 
			if(val == dp[u][i])
			{
				dp[u][i] = dp2[u][i];
			}
		}
 
		for(int i = 1 ; i <= k ; ++i)
		{
			ll val = max(dp[u][i], dp[u][i-1] + vis[u] - vet[v]);
 
			if(val > dp[v][i]) dp2[v][i] = dp[v][i], dp[v][i] = val;
			else if(val > dp2[v][i]) dp2[v][i] = val;
		}
 
		rotate(v, u);
 
		for(int i = 1 ; i <= k ; ++i) dp[u][i] = ant[u][i];
	}
}
 
int main()
{
	cin >> n >> k;
 
	for(int i = 1 ; i <= n ; ++i) cin >> vet[i];
 
	for(int i = 1 ; i < n ; ++i)
	{
		int u, v;
		cin >> u >> v;
 
		graph[u].push_back(v);
		graph[v].push_back(u);
	}
 
	for(int i = 1 ; i <= n ; ++i)
	{
		for(int v: graph[i])
		{
			vis[i] += vet[v];
		}
	}
 
	dfs(1);
	rotate(1);
 
	cout << ans << '\n';
}

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 2688 KB Output is correct
2 Correct 4 ms 2816 KB Output is correct
3 Correct 4 ms 2688 KB Output is correct
4 Correct 6 ms 2688 KB Output is correct
5 Correct 5 ms 2688 KB Output is correct
6 Correct 4 ms 2688 KB Output is correct

Subtask #2
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 2688 KB Output is correct
2 Correct 4 ms 2816 KB Output is correct
3 Correct 4 ms 2688 KB Output is correct
4 Correct 6 ms 2688 KB Output is correct
5 Correct 5 ms 2688 KB Output is correct
6 Correct 4 ms 2688 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 4992 KB Output is correct
9 Correct 6 ms 4480 KB Output is correct
10 Correct 8 ms 5248 KB Output is correct
11 Correct 8 ms 5132 KB Output is correct
12 Correct 7 ms 5248 KB Output is correct

Subtask #3
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 572 ms 230312 KB Output is correct
2 Correct 620 ms 230008 KB Output is correct
3 Correct 334 ms 182140 KB Output is correct
4 Correct 440 ms 252536 KB Output is correct
5 Correct 783 ms 254824 KB Output is correct
6 Correct 810 ms 254840 KB Output is correct
7 Correct 790 ms 254736 KB Output is correct

Subtask #4
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 2688 KB Output is correct
2 Correct 4 ms 2816 KB Output is correct
3 Correct 4 ms 2688 KB Output is correct
4 Correct 6 ms 2688 KB Output is correct
5 Correct 5 ms 2688 KB Output is correct
6 Correct 4 ms 2688 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 4992 KB Output is correct
9 Correct 6 ms 4480 KB Output is correct
10 Correct 8 ms 5248 KB Output is correct
11 Correct 8 ms 5132 KB Output is correct
12 Correct 7 ms 5248 KB Output is correct
13 Correct 572 ms 230312 KB Output is correct
14 Correct 620 ms 230008 KB Output is correct
15 Correct 334 ms 182140 KB Output is correct
16 Correct 440 ms 252536 KB Output is correct
17 Correct 783 ms 254824 KB Output is correct
18 Correct 810 ms 254840 KB Output is correct
19 Correct 790 ms 254736 KB Output is correct
20 Correct 790 ms 254788 KB Output is correct
21 Correct 156 ms 9592 KB Output is correct
22 Correct 807 ms 254884 KB Output is correct
23 Correct 390 ms 252544 KB Output is correct
24 Correct 795 ms 254960 KB Output is correct
25 Correct 309 ms 181740 KB Output is correct
26 Correct 560 ms 230452 KB Output is correct
27 Correct 527 ms 230304 KB Output is correct