Submission #443167

#	Time	Username	Problem	Language	Result	Execution time	Memory
443167		arwaeystoamneg	Beads and wires (APIO14_beads)	C++17	0 / 100	1 ms	204 KiB

beads

// EXPLOSION!
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
#include<chrono>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpll;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define mp make_pair
#define rsz resize
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define f first
#define s second
#define cont continue
#define endl '\n'
//#define ednl '\n'
#define test int testc;cin>>testc;while(testc--)
#define pr(a, b) trav(x,a)cerr << x << b; cerr << endl;
#define message cout << "Hello World" << endl;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; // for every grid problem!!
const ll linf = 4000000000000000000LL;
const ll inf = 998244353;//    1000000007

void pv(vi a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vll a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vector<vi>a) {
	F0R(i, sz(a)) { cout << i << endl; pv(a[i]); cout << endl; }
}void pv(vector<vll>a) { F0R(i, sz(a)) { cout << i << endl; pv(a[i]); }cout << endl; }void pv(vector<string>a) { trav(x, a)cout << x << endl; cout << endl; }
void setIO(string s) {
	ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef arwaeystoamneg
	if (sz(s))
	{
		freopen((s + ".in").c_str(), "r", stdin);
		if (s != "test1")
			freopen((s + ".out").c_str(), "w", stdout);
	}
#endif
}
int n;
vector<vpi>adj;
vi dp, dpusing;
vpi parent;
void dfs(int i, int p = -1)
{
	trav(x, adj[i])
	{
		if (x.f == p)continue;
		parent[x.f] = { i,x.s };
		dfs(x.f, i);
	}
	int best = -inf, sum = 0;
	vi t;
	trav(x, adj[i])
	{
		if (x.f == p)continue;
		sum += max(dp[x.f], dpusing[x.f]);
		best = max(best, dp[x.f] + x.s - max(dp[x.f], dpusing[x.f]));
		t.pb(dp[x.f] + x.s - max(dp[x.f], dpusing[x.f]));
	}
	dpusing[i] = sum + best + parent[i].s;
	int val = -inf;
	if (sz(t) >= 2)
	{
		sort(all(t));
		val = t[sz(t) - 2] + t[sz(t) - 1];
	}
	dp[i] = max(sum, sum + val);
}
int main()
{
	setIO("test1");
	cin >> n;
	adj.rsz(n);
	F0R(i, n - 1)
	{
		int x, y, z;
		cin >> x >> y >> z;
		adj[--x].pb({ --y,z });
		adj[y].pb({ x,z });
	}
	dp.rsz(n);
	dpusing.rsz(n);
	parent.rsz(n);
	parent[0] = { -1,-inf };
	dfs(0);
	cout << dp[0] << endl;
}

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