Submission #937503

#	Time	Username	Problem	Language	Result	Execution time	Memory
937503		IBory	Training (IOI07_training)	C++17	30 / 100	4 ms	1112 KiB

training

#include <bits/stdc++.h>
#define pii pair<int, int>
using namespace std;

const int MAX = 5005;
vector<int> G[MAX], T[MAX];
pii E[MAX];
int P[MAX], D[MAX], C[MAX], dp[MAX], temp[1 << 10];
int in[MAX], out[MAX], dn;

void DFS(int cur, int prev) {
	if (prev) G[cur].erase(find(G[cur].begin(), G[cur].end(), prev));
	in[cur] = ++dn;
	D[cur] = D[prev] + 1;
	P[cur] = prev;
	for (int next : G[cur]) DFS(next, cur);
	out[cur] = dn;
}

int LCA(int a, int b) {
	if (D[a] > D[b]) swap(a, b);
	while (D[a] != D[b]) b = P[b];
	while (a != b) a = P[a], b = P[b];
	return a;
}

int Find(int cur, int child) {
	for (int i = 0; i < G[cur].size(); ++i) {
		int n = G[cur][i];
		if (in[n] <= in[child] && in[child] <= out[n]) return (1 << i);
	}
	return 0;
}

void DFS2(int cur) {
	for (int next : G[cur]) DFS2(next);

	vector<pii> cost;
	for (int i = 0; i < G[cur].size(); ++i) {
		cost.emplace_back(1 << i, dp[G[cur][i]]);
	}

	for (int en : T[cur]) {
		auto [a, b] = E[en];
		int bit = 0, v = C[en];
		if (a != cur) bit |= Find(cur, a), v += dp[a];
		if (b != cur) bit |= Find(cur, b), v += dp[b];
		cost.emplace_back(bit, v);
	}

	int Z = (1 << G[cur].size());
	memset(temp, 0, sizeof(temp));
	for (int i = 0; i < Z; ++i) {
		for (auto [b, n] : cost) {
			if (i & b) continue;
			temp[i | b] = max(temp[i | b], temp[i] + n);
		}
	}

	dp[cur] = *max_element(temp, temp + 1024);
}

int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	int N, M, ans = 0, remain = 1;
	cin >> N >> M;
	for (int i = 1; i <= M; ++i) {
		int a, b, c;
		cin >> a >> b >> c;
		if (!c) {
			G[a].push_back(b);
			G[b].push_back(a);
		}
		else {
			E[remain] = {a, b};
			C[remain++] = c;
			ans += c;
		}
	}

	DFS(1, 0);
	for (int i = 1; i <= M - N + 1; ++i) {
		auto [a, b] = E[i];
		if (abs(D[a] - D[b]) & 1) continue;
		int c = LCA(a, b);
		T[c].push_back(i);
	}

	DFS2(1);
	ans -= dp[1];
	cout << ans;
	return 0;
}

Compilation message (stderr)

training.cpp: In function 'int Find(int, int)':
training.cpp:28:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |  for (int i = 0; i < G[cur].size(); ++i) {
      |                  ~~^~~~~~~~~~~~~~~
training.cpp: In function 'void DFS2(int)':
training.cpp:39:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |  for (int i = 0; i < G[cur].size(); ++i) {
      |                  ~~^~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 0 / 7
• Subtask 5: 0 / 9
• Subtask 6: 0 / 9
• Subtask 7: 0 / 9
• Subtask 8: 0 / 9
• Subtask 9: 0 / 9
• Subtask 10: 0 / 9
• Subtask 11: 0 / 9