Submission #536811

#	Time	Username	Problem	Language	Result	Execution time	Memory
536811		pavement	Election Campaign (JOI15_election_campaign)	C++17	100 / 100	304 ms	46228 KiB

election_campaign

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
#define int long long
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ppb pop_back
#define eb emplace_back
#define g0(a) get<0>(a)
#define g1(a) get<1>(a)
#define g2(a) get<2>(a)
#define g3(a) get<3>(a)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef double db;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef tuple<int, int, int> iii;
typedef tuple<int, int, int, int> iiii;
typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

int N, M, idx, a[100005], b[100005], c[100005], sz[100005], pre[100005], ft1[100005], ft2[100005], anc[100005][25], dep[100005];
vector<int> adj[100005], vec[100005];

int dfs(int n, int e = -1) {
	anc[n][0] = e;
	pre[n] = ++idx;
	for (int i = 1; i <= 20; i++)
		if (anc[n][i - 1] != -1)
			anc[n][i] = anc[anc[n][i - 1]][i - 1];
	for (auto u : adj[n])
		if (u != e) {
			dep[u] = dep[n] + 1;
			sz[n] += dfs(u, n);
		}
	return ++sz[n];
}

int lca(int u, int v) {
	if (dep[u] < dep[v]) swap(u, v);
	for (int i = 20; i >= 0; i--)
		if (dep[u] - (1 << i) >= dep[v]) u = anc[u][i];
	if (u == v) return u;
	for (int i = 20; i >= 0; i--)
		if (anc[u][i] != anc[v][i]) {
			u = anc[u][i];
			v = anc[v][i];
		}
	return anc[u][0];
}

inline int ls(int x) { return x & -x; }

void upd1(int l, int r, int v) {
	for (; l <= N; l += ls(l)) ft1[l] += v;
	for (r++; r <= N; r += ls(r)) ft1[r] -= v;
}

void upd2(int l, int r, int v) {
	for (; l <= N; l += ls(l)) ft2[l] += v;
	for (r++; r <= N; r += ls(r)) ft2[r] -= v;
}

int qry1(int p) {
	p = pre[p];
	int r = 0;
	for (; p; p -= ls(p)) r += ft1[p];
	return r;
}

int qry2(int p) {
	p = pre[p];
	int r = 0;
	for (; p; p -= ls(p)) r += ft2[p];
	return r;
}

int dp(int n, int e = -1) {
	int ret = 0;
	for (auto u : adj[n])
		if (u != e) ret += dp(u, n);
	upd1(pre[n], pre[n] + sz[n] - 1, ret);
	for (auto i : vec[n])
		ret = max(ret, qry1(a[i]) + qry1(b[i]) - qry1(n) - (qry2(a[i]) + qry2(b[i]) - qry2(n)) + c[i]);
	upd2(pre[n], pre[n] + sz[n] - 1, ret);
	return ret;
}

main() {
	memset(anc, -1, sizeof anc);
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> N;
	for (int i = 1, u, v; i < N; i++) {
		cin >> u >> v;
		adj[u].pb(v);
		adj[v].pb(u);
	}
	dfs(1);
	cin >> M;
	for (int i = 1; i <= M; i++) {
		cin >> a[i] >> b[i] >> c[i];
		vec[lca(a[i], b[i])].pb(i);
	}
	cout << dp(1) << '\n';
}

Compilation message (stderr)

election_campaign.cpp:95:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   95 | main() {
      | ^~~~

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