Submission #1107607

#	Time	Username	Problem	Language	Result	Execution time	Memory
1107607		vjudge1	Magic Tree (CEOI19_magictree)	C++17	0 / 100	15 ms	760 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;

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;
    for(int i =1; i<=n; i++) adj[i].clear();
    f.clear();
    timer = 1;
    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){
                if(zird(f[j].v, f[i].v) and f[j].d < f[i].d){
                    v[i] |= (1 << j);
                }
                if(zird(f[i].v, f[j].v) and f[i].d < f[j].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;
    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