Submission #947943

#	Time	Username	Problem	Language	Result	Execution time	Memory
947943		vqpahmad	Election Campaign (JOI15_election_campaign)	C++17	10 / 100	163 ms	83892 KiB

election_campaign

#include<bits/stdc++.h>
using namespace std;
#ifdef ONPC
#include"debug.h"
#else
#define debug(...) 42
#endif
#define endl '\n'
#define ll long long
#define pii pair<int,int>
#define F first
#define S second
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
#define int long long
template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
const int mod = 1e9 + 7;
const int MAXN = 1e6 + 15;
const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3f;
vector<int> adj[MAXN];
int fa[MAXN][20], dep[MAXN], dt[MAXN], ft[MAXN], timer = 1;
void dfs(int node, int par){
	dep[node] = dep[par] + 1;
	fa[node][0] = par;
	dt[node] = timer++;
	for (auto to : adj[node]){
		if (to != par) dfs(to, node);
	}
	ft[node] = timer++;
}
int lca(int u, int v){
	if (dep[u] > dep[v]) swap(u, v);
	for (int j = 19; j >= 0; j--){
		if (dep[fa[v][j]] >= dep[u]) v = fa[v][j];
	}
	if (u == v) return u;
	for (int j = 19; j >= 0; j--){
		if (fa[v][j] != fa[u][j]) v = fa[v][j], u = fa[u][j];
	}
	return fa[u][0];
}
vector<array<int, 3>> queries[MAXN];
ll dp[MAXN];
bool contain(int u, int v){
	return dt[u] <= dt[v] && ft[v] <= ft[u];
}
void solve(int node, int par){
	for (int to : adj[node]){
		if (to != par) {
			solve(to, node);
			dp[node] += dp[to];
		}
	}
	for (auto [u, v, c] : queries[node]){
		ll tm = c;
		for (int to : adj[u]){
			if (contain(to, v) || contain(to, u)) continue;
			tm += dp[to];
		}
		for (int to : adj[v]){
			if (contain(to, v) || contain(to, u)) continue;
			tm += dp[to];
		}
		if (node != u && node != v){
			for (int to : adj[node]){
				if (contain(to, v) || contain(to, u)) continue;
				tm += dp[to];
			}
		}
		ckmax(dp[node], tm);
	}
}
int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n;
	cin >> n;
	for (int i = 0; i < n - 1; i++){
		int u, v;
		cin >> u >> v;
		adj[u].pb(v);
		adj[v].pb(u);
	}
	dfs(1, 1);
	for (int j = 1; j < 20; j++){
		for (int i = 1; i <= n; i++){
			fa[i][j] = fa[fa[i][j - 1]][j - 1];
		}
	}
	int m;
	cin >> m;
	for (int i = 0; i < m; i++){
		int u, v, c;
		cin >> u >> v >> c;
		queries[lca(u, v)].pb({u, v, c});
	}
	solve(1, 1);
	cout << dp[1] << endl;
}

• Subtask 1: 0 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 0 / 30
• Subtask 5: 0 / 10
• Subtask 6: 0 / 40