Submission #668982

#	Time	Username	Problem	Language	Result	Execution time	Memory
668982		Dan4Life	Beads and wires (APIO14_beads)	C++17	0 / 100	1 ms	468 KiB

beads

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define all(a) a.begin(),a.end()
#define mp make_pair
#define fi first
#define se second
 
const int maxn = (int)1e4+10;
int n, num=0, ok;
int a[maxn], b[maxn], c[maxn];
vector<int> adj[maxn];
bool vis[maxn];

void dfs(int s){
    vis[s]=1; num++; int cnt = 0;
    for(auto u : adj[s]){
        if(adj[u].size()==2) cnt++;
        if(!vis[u]) dfs(u);
    }
    if(cnt>2)ok=0;
}

int32_t main()
{
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n; int ans = 0;
    for(int i = 0; i < n-1; i++) cin >> a[i] >> b[i] >> c[i];
    for(int mask = 0; mask < (1<<(n-1)); mask++){
        int sum = 0; ok=1;
        for(int i = 1; i <= n; i++) adj[i].clear(), vis[i]=false;
        for(int i = 0; i < n-1; i++) sum+=!!(mask&(1<<i))*c[i];
        for(int i = 0; i < n-1; i++) 
            if(mask&(1<<i)) adj[a[i]].pb(b[i]);
        for(int i = 1; i <= n; i++){
            num=0; if(!vis[i]) dfs(i), ok&=(num%2==1);
        }
        if(ok) ans = max(ans, sum);
    }
    cout << ans;
}

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