Submission #947963

#	Time	Username	Problem	Language	Result	Execution time	Memory
947963		vqpahmad	Election Campaign (JOI15_election_campaign)	C++17	100 / 100	212 ms	111876 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;
const int off = (1<<18);
struct sgt {
#define ls (idx<<1)
#define rs (idx<<1|1)
	ll t[off<<1], lazy[MAXN];
	int unit = 0;
	void pull(int idx){
		t[idx] = t[ls]+t[rs];
	}
	void push(int idx){
		if (!lazy[idx]) return;
		t[idx] += lazy[idx];
		if (idx < off){
			lazy[ls] += lazy[idx];
			lazy[rs] += lazy[idx];
		}
		lazy[idx] = 0;
	}
	void update(int idx, int u){
		t[idx+=off] = u;
		while (idx/=2)
			pull(idx);
	}
	ll get(int idx){
		ll res = t[idx += off];
		while (idx/=2)
			res += t[idx];
		return res;
	}
	int get(int l, int r, int idx=1, int lo=0, int hi=off){
		if (r <= lo || hi <= l) 
			return unit;
		if (l <= lo && hi <= r)
			return t[idx];
		int mi = (lo+hi)>>1;
		return get(l, r, ls, lo, mi)+get(l, r, rs, mi, hi);
	}
	void update(int l, int r, int v, int idx=1, int lo=0, int hi=off){
		if (r <= lo || hi <= l) 
			return;
		if (l <= lo && hi <= r){
			t[idx] += v;
			return;
		}
		int mi = (lo+hi)>>1;
		update(l, r, v, ls, lo, mi);
		update(l, r, v, rs, mi, hi);
		return;
	}
} seg1, seg2;
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 dp1[MAXN], dp2[MAXN];
//  dp1 for best answer
//  dp2 for sum of childern
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);
			dp1[node] += dp1[to];
		}
	}
	dp2[node] = dp1[node];
	seg2.update(dt[node], ft[node], dp2[node]);
	for (auto [u, v, c] : queries[node]){
		debug(node, u, v, c);
		debug(seg2.get(dt[u]), seg2.get(dt[v]), seg2.get(dt[node]), seg2.get(dt[fa[node][0]]));
		ll tm = c + seg2.get(dt[u]) + seg2.get(dt[v]) - seg2.get(dt[node]) - seg2.get(dt[fa[node][0]]);
		tm -= seg1.get(dt[u]) + seg1.get(dt[v]);
		ckmax(dp1[node], tm);
	}
	seg1.update(dt[node], ft[node], dp1[node]);
	debug(node, dp1[node], dp2[node]);
}
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, 0);
	for (int j = 1; j < 20; j++){
		for (int i = 1; i <= n; i++){
			fa[i][j] = fa[fa[i][j - 1]][j - 1];
		}
	}
	for (int i = 1; i <= n; i++){
		debug(i, dt[i], ft[i]);
	}
	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, 0);
	cout << dp1[1] << endl;
}

Compilation message (stderr)

election_campaign.cpp: In function 'void solve(long long int, long long int)':
election_campaign.cpp:6:20: warning: statement has no effect [-Wunused-value]
    6 | #define debug(...) 42
      |                    ^~
election_campaign.cpp:112:3: note: in expansion of macro 'debug'
  112 |   debug(node, u, v, c);
      |   ^~~~~
election_campaign.cpp:6:20: warning: statement has no effect [-Wunused-value]
    6 | #define debug(...) 42
      |                    ^~
election_campaign.cpp:113:3: note: in expansion of macro 'debug'
  113 |   debug(seg2.get(dt[u]), seg2.get(dt[v]), seg2.get(dt[node]), seg2.get(dt[fa[node][0]]));
      |   ^~~~~
election_campaign.cpp:6:20: warning: statement has no effect [-Wunused-value]
    6 | #define debug(...) 42
      |                    ^~
election_campaign.cpp:119:2: note: in expansion of macro 'debug'
  119 |  debug(node, dp1[node], dp2[node]);
      |  ^~~~~
election_campaign.cpp: In function 'int32_t main()':
election_campaign.cpp:6:20: warning: statement has no effect [-Wunused-value]
    6 | #define debug(...) 42
      |                    ^~
election_campaign.cpp:139:3: note: in expansion of macro 'debug'
  139 |   debug(i, dt[i], ft[i]);
      |   ^~~~~

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