Submission #967642

#	Time	Username	Problem	Language	Result	Execution time	Memory
967642		pragmatist	Beads and wires (APIO14_beads)	C++17	0 / 100	9 ms	25212 KiB

beads

//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")
 
#include<bits/stdc++.h>	
 
using namespace std;
 
#define all(a) a.begin(), a.end()                                                   
#define rall(a) a.rbegin(), a.rend()                 
#define sz(a) (int)a.size()
#define s second
#define f first
 
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
 
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
     
vector<pii> rid = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
vector<pii> dir = {{-1, -1}, {-1, 1}, {1, -1}, {1, 1}};
 
const int N = 1e6 + 1, mod = 1e9 + 7;
 
const ll inf = 2e9;
 
double eps = 1e-15;
                                                
bool flg = 0;
 
int was[N], ok = 1;
vector<int> g[N];
 
int dfs(int u, int p) {
	int cnt = (u != p);
	was[u] = 1;
	for (int to: g[u]) {
		if (to == p) continue;
		cnt += dfs(to, u);
	}
	if (cnt > 2) ok = 0;
	return (cnt & 1);
}
 
void slv() {
	int n;
	cin >> n;
	int u[n], v[n], w[n];
	for (int i = 0; i < n - 1; i++) {
    	cin >> u[i] >> v[i] >> w[i];
    }
    int mx = 0;
    for (int msk = 0; msk < (1 << (n - 1)); msk++) {
    	int sum = 0;
    	for (int i = 0; i < n - 1; i++) {
    		if (msk >> i & 1) {
    			g[u[i]].push_back(v[i]);
    			g[v[i]].push_back(u[i]);
    			sum += w[i];
    		}
    	}
    	ok = 1;
    	for (int i = 1; i <= n; i++) {
    		if (!was[i] && dfs(i, i)) ok = 0;
    	}
    	for (int i = 1; i <= n; i++) {
    		g[i].clear();
    		was[i] = 0;
    	}
    	if (ok) mx = max(mx, sum);
    }
    cout << mx;
}                                                                           
 
main() {
	//freopen("input.txt", "r", stdin);                                                                                     
	//freopen("output.txt", "w", stdout);                                                                                     
	ios_base::sync_with_stdio(0);	                                                                                       
	cin.tie(0);
	int tp = 1;
	if (flg) cin >> tp;
	while (tp--) {  	
		slv();
	}
}

Compilation message (stderr)

beads.cpp:75:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   75 | main() {
      | ^~~~

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