Submission #120938

#	Time	Username	Problem	Language	Result	Execution time	Memory
120938		thiago4532	Pipes (BOI13_pipes)	C++17	35 / 100	272 ms	25344 KiB

pipes

#include <bits/stdc++.h>

using namespace std;
typedef pair<int, int> pii;
const int maxn = 1e5 + 10;
const int maxm = 5e5 + 10;
vector<int> grafo[maxn];
int n;
int s[maxn];
map<pair<int, int>, int> mapa;
int val[maxn], ans[maxn];

namespace tree{

int nivel[maxn], pai[maxn], soma[maxn];
void dfs(int u, int p = 0) {
	pai[u] = p;

	for(auto v : grafo[u]) {
		if(v == p) continue;
		nivel[v] = nivel[u] + 1;
		dfs(v, u);
	}
}

};

int main() {
	int m;

	cin >> n >> m;
	if(m > n) {
		cout << "0\n";
		return 0;
	}
	int total = 0;
	for(int i=1;i<=n;i++)
		cin >> s[i], s[i] *= 2, total += s[i];

	for(int i=1;i<=m;i++) {
		int a, b;
		cin >> a >> b;
		grafo[a].push_back(b);
		grafo[a].push_back(b);
		mapa[{a, b}] = i;
		mapa[{b, a}] = i;
	}
	if(n - 1 == m) {
		tree::dfs(1);
		vector<pii> arr;
		for(int i=1;i<=n;i++)
			arr.push_back({tree::nivel[i], i});
		sort(arr.begin(), arr.end(), greater<pii>());

		for(auto e : arr) {
			int v = e.second, u = tree::pai[v];

			tree::soma[u] += (s[v] - tree::soma[v]);
			ans[mapa[{u, v}]] = (s[v] - tree::soma[v]);
		}

		for(int i=1;i<=m;i++)
			cout << ans[i] << "\n";

	}
	return 0;
}

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