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Submission #319199

# Submission time Handle Problem Language Result Execution time Memory
319199 2020-11-04T13:40:50 Z VodkaInTheJar Dynamite (POI11_dyn) C++14
10 / 100
 1478 ms 26468 KB 
#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#define endl '\n'

using namespace std;

const int maxn = 3e5 + 3; 

int n, m; 
bool is[maxn];
vector <int> adj[maxn];
void read()
{
	cin >> n >> m;
	for (int i = 1; i <= n; i++)
	cin >> is[i];
	
	for (int i = 1; i <= n-1; i++)
	{
		int a, b;
		cin >> a >> b;
		
		adj[a].push_back(b);
		adj[b].push_back(a);
	}
}

int cnt;
int dfs(int ver, int par, int x)
{
	int cover = 0, need_to_cover = 0;
	for (auto i: adj[ver])
	if (i != par)
	{
		int curr = dfs(i, ver, x);
		if (curr > 0)
		cover = max(cover, curr);
		
		else 
		if (curr < 0)
		need_to_cover = max(need_to_cover, -curr);
	}
	
	if (need_to_cover >= x)
	{
		cnt++;
		return x; 
	}
	
	need_to_cover = max(need_to_cover, (int)is[ver]);
	if (need_to_cover == 0)
	return max(0, cover - 1);
	
	else 
	if (cover >= need_to_cover)
	return max(0, cover - 1);
	
	else
	return -(need_to_cover + 1);
}

bool can(int x)
{
	cnt = 0;
	if (dfs(1, -1, x) < 0)
	cnt++;
    
    return cnt <= m; 	
}

void solve()
{
	int low = 0, high = n; 
	while (low < high)
	{
		int mid = (low + high) / 2;
		if (can(mid))
		high = mid;
		
		else 
		low = mid+1;
	}
	
	cout << low << endl;
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);

	read();
	solve();
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 7404 KB Output is correct
2 Correct 5 ms 7404 KB Output is correct
3 Correct 5 ms 7404 KB Output is correct
4 Incorrect 6 ms 7404 KB Output isn't correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 7404 KB Output is correct
2 Correct 5 ms 7404 KB Output is correct
3 Incorrect 5 ms 7532 KB Output isn't correct

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 6 ms 7404 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 7404 KB Output is correct
2 Correct 6 ms 7404 KB Output is correct

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 12 ms 7916 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 49 ms 9708 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 226 ms 11292 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 762 ms 14660 KB Output is correct
2 Incorrect 868 ms 18964 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 1478 ms 20196 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1353 ms 26468 KB Output is correct
2 Incorrect 1211 ms 22588 KB Output isn't correct
3 Halted 0 ms 0 KB -