Submission #734170

#	Time	Username	Problem	Language	Result	Execution time	Memory
734170		Abrar_Al_Samit	Beads and wires (APIO14_beads)	C++17	0 / 100	4 ms	6560 KiB

beads

#include<bits/stdc++.h>
using namespace std;


const int nax = 200005;

vector<pair<int,int>>g[nax];

int dp[nax][2], n;

int solve(int v, int topar, int p = -1) {
	int &ret = dp[v][(topar>0)];
	if(ret!=-1) return ret;
	ret = 0;

	int base = 0;
	for(auto [u, w] : g[v]) if(u!=p) {
		base += solve(u, w, v);
	}

	ret = base;
	if(topar>0) {
		for(auto [u, w] : g[v]) if(u!=p) {
			int cur = base - solve(u, w, v) + solve(u, 0, v) + topar + w;
			ret = max(ret, cur);
		}
	}

	for(int i=0; i<g[v].size(); ++i) {
		for(int j=i+1; j<g[v].size(); ++j) {
			auto [u1, w1] = g[v][i];
			auto [u2, w2] = g[v][j];

			if(u1==p || u2==p) continue;

			int cur = base - solve(u1, w1, v) - solve(u2, w2, v) + solve(u1, 0, v)
				+ solve(u2, 0, v) + w1 + w2;

			ret = max(ret, cur);
		}
	}
	return ret;
}
void PlayGround() {
	cin>>n;
	for(int i=1; i<n; ++i) {
		int u, v, w;
		cin>>u>>v>>w;
		g[u].emplace_back(v, w);
		g[v].emplace_back(u, w);
	}	

	memset(dp, -1, sizeof dp);
	cout<<solve(1, 0)<<'\n';

	// cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
}
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	PlayGround();
	return 0;
}

Compilation message (stderr)

beads.cpp: In function 'int solve(int, int, int)':
beads.cpp:29:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |  for(int i=0; i<g[v].size(); ++i) {
      |               ~^~~~~~~~~~~~
beads.cpp:30:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |   for(int j=i+1; j<g[v].size(); ++j) {
      |                  ~^~~~~~~~~~~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 15
• Subtask 3: 0 / 29
• Subtask 4: 0 / 43