Submission #1280199

#	Time	Username	Problem	Language	Result	Execution time	Memory
1280199		PlayVoltz	Election Campaign (JOI15_election_campaign)	C++20	100 / 100	172 ms	43144 KiB

election_campaign

#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
using namespace std;
 
#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second

int counter=0;
vector<int> depth, in, out, dp, ft;
vector<vector<int> > graph, twok;
vector<vector<pair<pii, int> > > quer;

int query(int i){
	int res=0;
	for (;i;i-=i&-i)res+=ft[i];
	return res;
}

void up(int i, int v){
	for (;i<ft.size();i+=i&-i)ft[i]+=v;
}

void dfs(int node, int p, int d){
	in[node]=++counter;
	twok[node][0]=p;
	depth[node]=d;
	for (int i=1; i<20; ++i)twok[node][i]=twok[twok[node][i-1]][i-1];
	for (auto num:graph[node])if (num!=p)dfs(num, node, d+1);
	out[node]=counter;
}

int lca(int a, int b){
	if (depth[a]<depth[b])swap(a, b);
	for (int i=0, k=depth[a]-depth[b]; i<20; ++i)if (k&(1<<i))a=twok[a][i];
	if (a==b)return a;
	for (int i=19; i>=0; --i)if (twok[a][i]!=twok[b][i])a=twok[a][i], b=twok[b][i];
	return twok[a][0];
}

void dfs2(int node, int p){
	int sum=0;
	for (auto num:graph[node])if (num!=p)dfs2(num, node), sum+=dp[num];
	for (auto c:quer[node])dp[node]=max(dp[node], query(in[c.fi.fi])+query(in[c.fi.se])+sum+c.se);
	dp[node]=max(dp[node], sum);
	up(in[node], sum-dp[node]);
	up(out[node]+1, dp[node]-sum);
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n, m, a, b, c;
	cin>>n;
	ft.resize(n+1, 0);
	dp.resize(n+1, 0);
	graph.resize(n+1);
	twok.resize(n+1, vector<int>(20));
	in.resize(n+1);
	out.resize(n+1);
	depth.resize(n+1);
	quer.resize(n+1);
	for (int i=1; i<n; ++i){
		cin>>a>>b;
		graph[a].pb(b);
		graph[b].pb(a);
	}
	dfs(1, 1, 0);
	cin>>m;
	while (m--)cin>>a>>b>>c, quer[lca(a, b)].pb(mp(mp(a, b), c));
	dfs2(1, 1);
	cout<<dp[1];
}

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