Submission #198626

#	Time	Username	Problem	Language	Result	Execution time	Memory
198626		red1108	Beads and wires (APIO14_beads)	C++17	0 / 100	8 ms	5116 KiB

beads

#include<bits/stdc++.h>
#include<ext/rope>
using namespace std;
using namespace __gnu_cxx;
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false);cin.tie(0)
#define fopen freopen("input.txt", "r", stdin)
#define eb emplace_back
#define em emplace
#define prec(a) cout<<fixed;cout.precision(a);
#define all(a) (a).begin(), (a).end()
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef tuple<int,int,int> tiii;
const ll INF = 2e16;
const int inf = 2e9;
template<class T>
void pr(T t) {cout << t << " ";}
template<class T, class ...Args>
void pr(T a, Args ...args) {cout << a << " ";pr(args...);}
template<class ...Args>
void prl(Args ...args) {pr(args...);cout << endl;}

int n;
const int MAXN=200010;
ll t[MAXN],s[MAXN],b[MAXN],ans;
vector<pll> tree[MAXN];
void dfs(int x, int par, ll bac){
	ll sum=0;
	vector<ll> h;
	int c=0;
	for(auto i:tree[x]) if(i.fi!=par){
		dfs(i.fi,x,i.se);
		ll tmp = max({t[i.fi],s[i.fi],b[i.fi]});
		sum+=tmp;
		c++;
		h.eb(-i.se-max(s[i.fi],b[i.fi])+tmp);
	}
	sort(h.begin(),h.end());
	if(par&&c>=1) t[x]=sum - h[0] + bac;
	if(c>=2) s[x]=sum - h[0] - h[1];
	b[x]=sum;
	ans = max({ans, t[x], s[x], b[x]});
}
int main(){
	fastio;
	cin>>n;
	for(int i=1;i<n;i++){
		int a, b, c;cin>>a>>b>>c;
		tree[a].eb(b,c);
		tree[b].eb(a,c);
	}
	dfs(1,0,0);
	cout<<ans;
}

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