Submission #1107605

#	Time	Username	Problem	Language	Result	Execution time	Memory
1107605		vjudge1	Magic Tree (CEOI19_magictree)	C++17	0 / 100	1 ms	592 KiB

magictree

/******************************************************
| '_ \ / _` |/ __| '_ ` _ \ / _` | '_ \
| |_) | (_| | (__| | | | | | (_| | | | |
| .__/ \__,_|\___|_| |_| |_|\__,_|_| |_|
|_|

__|      |____________________________________________
     ,--.    ,--.          ,--.   ,--.
    |oo  | _  \  `.       | oo | |  oo|
o  o|~~  |(_) /   ;       | ~~ | |  ~~|o  o  o  o  o
    |/\/\|   '._,'        |/\/\| |/\/\|
__________________        ____________________________
******************************************************/

#include <bits/stdc++.h>
#define db(x) cerr << #x << ": " << x << endl
#define print cerr << "Ah shit, here we go again" << endl
#define int long long int
#define vii vector<int>
#define pii pair<int ,int>
#define vpi vector< pii >
#define ff first
#define ss second
#define mp make_pair
#define mod 1000000007

using namespace std;

const int maxn = 100;

int n, m, k;

struct mive{
	int v, d, w;
};

int st[maxn], fn[maxn], timer = 1;

vector<int> adj[maxn];
vector<mive> f;

void dfs(int v, int mpar = 0){
	st[v] = timer++;
	for(auto u : adj[v]){
		if(u != mpar){
			dfs(u, v);
		}
	}
	fn[v] = timer++;
}

bool zird(int u, int v){
	return st[u] >= st[v] and fn[u] <= fn[v];
}

void solve(){
	cin >> n >> m >> k;
	f.clear();
	for(int i = 2; i <= n; i++){
		int x;
		cin >> x;
		adj[x].push_back(i);
		adj[i].push_back(x);
	}
	for(int i = 0; i < m; i++){
		int x, y, z;
		cin >> x >> y >> z;
		f.push_back({x, y, z});
	}
	dfs(1);
	vector<int> v(m, 0);
	for(int i = 0; i < m; i++){
		for(int j = 0; j < m; j++){
			if(i != j and zird(f[j].v, f[i].v) and f[j].d <= f[i].d){
				v[i] |= (1 << j);
			}
		}
	}
	int ans = 0;
	for(int mask = 0; mask < (1 << m); mask++){
		bool valid = true;
		for(int i = 0; i < m and valid; i++) if(mask & (1 << i)){
			if(v[i] & mask){
				valid = false;
			}
		}
		if(valid){
			ans = max(ans, (int)__builtin_popcount(mask));
		}
	}
	cout << ans << endl;
}

signed main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);
	int t = 1;
	// cin >> t;
	while(t--){
		solve();
	}
	return 0;
}

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