Submission #555861

#	Time	Username	Problem	Language	Result	Execution time	Memory
555861		blue	Pipes (BOI13_pipes)	C++17	35 / 100	67 ms	12492 KiB

pipes

#include <iostream>
#include <vector>
using namespace std;

using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
using vpii = vector<pii>;
using vll = vector<ll>;

const int mx = 100'000;

int N, M;
vpii edge[1+mx];
vll c(1+mx);


vll x(1+mx);

void dfs(int u, int p)
{
	for(pii vp : edge[u])
	{
		int v = vp.first;
		int e = vp.second;

		if(v == p) continue;
		dfs(v, u);

		x[e] = 2*c[v];

		c[v] = 0;
		c[u] -= c[v];
	}
}

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

	int N, M;
	cin >> N >> M;

	if(M > N)
	{
		cout << "0\n";
		return 0;
	}

	for(int i = 1; i <= N; i++) cin >> c[i];

	for(int j = 1; j <= M; j++)
	{
		int u, v;
		cin >> u >> v;
		edge[u].push_back({v, j});
		edge[v].push_back({u, j});
	}

	if(M == N-1)
	{
		dfs(1, 0);
	}

	for(int e = 1; e <= M; e++) 
		cout << x[e] << '\n';
}

• Subtask 1: 0 / 30
• Subtask 2: 35 / 70