Submission #924082

#	Time	Username	Problem	Language	Result	Execution time	Memory
924082		KiaRez	Election Campaign (JOI15_election_campaign)	C++17	100 / 100	302 ms	48844 KiB

election_campaign

/*
    IN THE NAME OF GOD
*/
#include <bits/stdc++.h>

// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
typedef long double ld;

#define F                                      first
#define S                                      second
#define Mp                                     make_pair
#define pb                                     push_back
#define pf                                     push_front
#define size(x)                                ((ll)x.size())
#define all(x)                                 (x).begin(),(x).end()
#define kill(x)		                           cout << x << '\n', exit(0);
#define fuck(x)                                cout << "(" << #x << " , " << x << ")" << endl
#define endl                                   '\n'

const int N = 2e5+23, lg = 18;
ll Mod = 1e9+7; //998244353;

inline ll MOD(ll a, ll mod=Mod) {a%=mod; (a<0)&&(a+=mod); return a;}
inline ll poww(ll a, ll b, ll mod=Mod) {
    ll ans = 1;
    a=MOD(a, mod);
    while (b) {
        if (b & 1) ans = MOD(ans*a, mod);
        b >>= 1;
        a = MOD(a*a, mod);
    }
    return ans;
}

ll n, m, fen[N], dp[N], sum[N];
int tim, tin[N], tout[N], h[N], par[lg][N];
vector<int> adj[N];
vector<vector<ll>> vec[N];

void upd(int pos, ll val) {while(pos<N) {fen[pos]+=val; pos+=(pos&(-pos));}}
ll qry(int pos) {
	ll res = 0; while(pos > 0) {res += fen[pos]; pos-=(pos&(-pos));} return res;
}
void add(int l, int r, ll val) {upd(l, val); upd(r, -val);}

int getPar(int v, int dist) {
	for(int i=0; i<lg; i++) {
		if((dist>>i)%2==1) v=par[i][v];
	} return v;
}

int LCA(int v, int u) {
	if(h[u]<h[v]) swap(v,u);
	u = getPar(u, h[u]-h[v]);
	if(v==u) return v;
	for(int i=lg-1; i>=0; i--) {
		if(par[i][v] != par[i][u]) v=par[i][v], u=par[i][u];
	}
	return par[0][v];
}

void init(int v, int p=0) {
	par[0][v] = p, h[v] = h[p] + 1, tin[v] = ++tim;
	for(int i=1; i<lg; i++) {
		par[i][v] = par[i-1][par[i-1][v]];
	}
	for(int u : adj[v]) {
		if(u == p) continue;
		init(u, v);
	}
	tout[v] = tim+1;
}

void dfs(int v, int p=0) {
	for(int u : adj[v]) {
		if(u == p) continue;
		dfs(u, v);
		dp[v] += dp[u];
		sum[v] += dp[u];
	}
	for(auto it : vec[v]) {
		int a,b;
		if(it[0]!=v) a=getPar(it[0],h[it[0]]-h[v]-1);
		else a = 0;
		if(it[1]!=v) b=getPar(it[1],h[it[1]]-h[v]-1);
		else b = 0;
		dp[v] = max(dp[v], qry(tin[it[0]])+qry(tin[it[1]])+it[2]+sum[v]-dp[a]-dp[b]);
	}
	add(tin[v], tin[v]+1, sum[v]);
	for(int u : adj[v]) {
		if(u == p) continue;
		add(tin[u], tout[u], sum[v]-dp[u]);
	}
}

int main () {
	// ios_base::sync_with_stdio(false), cin.tie(0);

	cin>>n;
	for(int v,u,i=1; i<n; i++) {
		cin>>v>>u;
		adj[v].pb(u); adj[u].pb(v);
	}

	init(1);
	cin>>m;
	for(int a,b,c,i=1; i<=m; i++) {
		cin>>a>>b>>c;
		vec[LCA(a, b)].pb({a, b, c});
	}

	dfs(1);
	cout<<dp[1]<<endl;

	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