Submission #264535

#	Time	Username	Problem	Language	Result	Execution time	Memory
264535		Atalasion	Election Campaign (JOI15_election_campaign)	C++14	100 / 100	481 ms	54008 KiB

election_campaign

//khodaya khodet komak kon
#include <bits/stdc++.h>

#define F first
#define S second
#define pb push_back
#define all(x) x.begin(), x.end()
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
#define int long long

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

const int N = 300000 + 10;
const ll MOD = 1000000000 + 7;
const ll INF = 1000000010;
const ll LOG = 19;

int par[N][LOG], n, q, A[N], B[N], C[N], h[N], st[N], ft[N], Time, fen[N], dp[N];
vi G[N], Q[N];

inline void add(int id, int x){
	for (; id < N; id += (id & (-id))) fen[id] += x;
}

inline int get(int id){
	int res = 0;
	for (; id > 0; id -= (id & (-id))) res += fen[id];
	return res;
}

void DFS(int v = 1, int p = 0){
	st[v] = ++Time;
	par[v][0] = p;
	for (int i = 1; i < LOG; i++) par[v][i] = par[par[v][i - 1]][i - 1];
	for (auto u:G[v]){
		if (u == p)continue;
		h[u] = h[v] + 1;
		DFS(u, v);
	}
	ft[v] = Time + 1;
}

int getpar(int v, int k){
	for (int i = 0; i < LOG; i++){
		if (k & (1 << i)) v = par[v][i];
	}
	return v;
}
	
int LCA(int v, int u){
	if (h[v] < h[u]) swap(v, u);
	v = getpar(v, h[v] - h[u]);
	if (v == u) return v;
	for (int i = LOG - 1; i >= 0; i--){
		if (par[v][i] != par[u][i]) v = par[v][i], u = par[u][i];
	}
	return par[v][0];
}

void DFS2(int v = 1, int p = 0){
	int sm = 0;
	for (auto u:G[v]){
		if (u == p) continue;
		DFS2(u, v);
		sm += dp[u];
	}
	dp[v] = sm;
	for (auto u:Q[v]){
		int lca = LCA(A[u], B[u]);
		if (h[A[u]] < h[B[u]]) swap(A[u], B[u]);
		if (lca == B[u]){
			int vv = getpar(A[u], h[A[u]] - h[v] - 1);
			dp[v] = max(dp[v], C[u] + sm - dp[vv] + get(st[A[u]]));
		}else{
			int vv = getpar(A[u], h[A[u]] - h[v] - 1), uu = getpar(B[u], h[B[u]] - h[v] - 1);
			dp[v] = max(dp[v], C[u] + sm - dp[uu] - dp[vv] + get(st[A[u]]) + get(st[B[u]]));
		}
	}
	add(st[v], sm);
	add(st[v] + 1, -sm);
	for (auto u:G[v]){
		if (u == p) continue;
		add(st[u], sm - dp[u]);
		add(ft[u], -(sm - dp[u]));
	}
}

int32_t main(){
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	cin >> n;
	for (int i = 0; i < n - 1; i++){
		int v, u;
		cin >> v >> u;
		G[v].pb(u), G[u].pb(v);
	}
	DFS();
	cin >> q;
	for (int i = 1; i <= q; i++){
		cin >> A[i] >> B[i] >> C[i];
		//cout << LCA(A[i], B[i]) << '\n';
		Q[LCA(A[i], B[i])].pb(i);
	}
	DFS2();	
	cout << dp[1];









	return 0;
}

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