Submission #836943

#	Time	Username	Problem	Language	Result	Execution time	Memory
836943		Juan	Magic Tree (CEOI19_magictree)	C++17	14 / 100	149 ms	21596 KiB

magictree

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define tii tuple<int,int,int,int>
#define pii pair<int,int>
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
const int maxn = 1e5 + 5;

vector<int> g[maxn];
int tin[maxn], tout[maxn], pai[maxn], ans_arr[maxn], depth[maxn];
vector<tii> fruits;
int n;

int timer=1;
void elr_tr(int u, int p){
	tin[u] = timer++;
	depth[u] = depth[p]+1;

	for(int v : g[u]) if(v!=p){
		elr_tr(v,u);
	}
	tout[u] = timer;
}

struct SEG{
	int tree[4*maxn];

	void fupd(int node, int tl, int tr, int id, int val){
		if(tl>id || tr<id) return;
		if(tl==tr){tree[node] = val; return;}

		int mid = (tl+tr)>>1;
		int f1 = node*2, f2 = node*2+1;
		fupd(f1, tl, mid, id, val), fupd(f2, mid+1, tr, id, val);
		tree[node] = max(tree[f1], tree[f2]);
	}
	void upd(int id, int val){fupd(1, 1, n, id, val);}

	int fquery(int node, int tl, int tr, int l, int r){
		if(tl>r || tr<l) return 0;
		if(tl>=l && tr<=r) return tree[node];

		int mid = (tl+tr)>>1;
		int f1 = node*2, f2 = node*2+1;
		return max(fquery(f1, tl, mid, l, r), fquery(f2, mid+1, tr, l, r));
	}
	int query(int l, int r){return fquery(1, 1, n, l, r);}
}seg;

int solve(int u, int p){
	int aux = 0;
	for(int v : g[u]) if(v!=p){
		aux += solve(v,u);
	}
	return max(ans_arr[u], aux);
}

int32_t main(){
	int m, k; cin >> n >> m >> k;
	for(int i = 2; i <= n; i++){
		int p; cin >> p;
		pai[i] = p;
		g[i].push_back(p);
		g[p].push_back(i);
	}

	elr_tr(1,1);

	for(int i = 0; i < m; i++){
		int v, d, w; cin >> v >> d >> w;
		fruits.push_back({d,-depth[v],v,w});
	}

	sort(all(fruits));
	for(auto[d,dep,u,w] : fruits){
		ans_arr[u] = w;
		for(int v : g[u]) if(v!=pai[u]) ans_arr[u] += seg.query(tin[v], tout[v]);
		seg.upd(tin[u], ans_arr[u]);
	}

	cout << solve(1,1) << '\n';
}

• Subtask 1: 0 / 6
• Subtask 2: 3 / 3
• Subtask 3: 11 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 16
• Subtask 6: 0 / 13
• Subtask 7: 0 / 22
• Subtask 8: 0 / 17