Submission #944283

#	Time	Username	Problem	Language	Result	Execution time	Memory
944283		phoenix0423	Harbingers (CEOI09_harbingers)	C++17	100 / 100	79 ms	21272 KiB

harbingers

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define fastio ios::sync_with_stdio(false), cin.tie(0)
#pragma GCC optimize("Ofast")
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define int long long
#define lowbit(x) x&-x
const int INF = 1e9 + 7;
const int maxn = 1e5 + 5;
vector<pll> adj[maxn];
int a[maxn], b[maxn], ans[maxn];
int n;

int dep[maxn];
int cur_size = 1;
struct line{
	int m, k;
	line(){}
	line(int _m, int _k) : m(_m), k(_k){}
	int operator()(int x){
		return m * x + k;
	}
};
line st[maxn];
double intersect(line a, line b){
	return double(a.k - b.k) / (b.m - a.m);
}
void dfs(int pos, int prev){
	// cout<<pos<<" : \n";
	// for(int i = 0; i < cur_size; i++) cout<<st[i].m<<" "<<st[i].k<<"\n";
	if(pos){
		int l = 0, r = cur_size - 1;
		while(l < r){
			int m = (l + r) / 2;
			if(st[m](b[pos]) <= st[m + 1](b[pos])) r = m;
			else l = m + 1;
		}
		ans[pos] = a[pos] + b[pos] * dep[pos] + st[l](b[pos]);
	}
	line cur = line(-dep[pos], ans[pos]);
	int l = 0, r = cur_size - 1;
	while(l < r){
		int m = (l + r) / 2;
		if(intersect(st[m], cur) >= intersect(st[m + 1], cur)){
			// cout<<"kill : "<<m<<" "<<intersect(st[m], cur)<<" "<<intersect(st[m + 1], cur)<<"\n";
			r = m;
		} 
		else l = m + 1;
	}
	int prv_size = cur_size;
	auto prv_line = st[l + 1];
	cur_size = l + 2;
	st[l + 1] = cur;
	for(auto [x, w] : adj[pos]){
		if(x == prev) continue;
		dep[x] = dep[pos] + w;
		dfs(x, pos);
	}
	cur_size = prv_size;
	st[l + 1] = prv_line;
}

signed main(void){
	fastio;
	cin>>n;
	for(int i = 0; i < n - 1; i++){
		int a, b, w;
		cin>>a>>b>>w;
		a--, b--;
		adj[a].eb(b, w);
		adj[b].eb(a, w);
	}
	for(int i = 1; i < n; i++){
		cin>>a[i]>>b[i];
	}
	dfs(0, -1);
	for(int i = 1; i < n; i++) cout<<ans[i]<<" ";
	cout<<"\n";
}

• Subtask 1: 100 / 100