Submission #831299

#	Time	Username	Problem	Language	Result	Execution time	Memory
831299		GrindMachine	Firefighting (NOI20_firefighting)	C++17	0 / 100	4 ms	724 KiB

Firefighting

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 3e3 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

vector<pll> adj[N];
vector<ll> good[N];
ll n,k;

void dfs(ll u, ll p, ll root, ll d){
    if(d > k) return;
    good[root].pb(u);
    for(auto [v,w] : adj[u]){
        if(v == p) conts;
        dfs(v,u,root,d+w);
    }
}

void solve(int test_case)
{
    cin >> n >> k;
    rep1(i,n-1){
        ll u,v,w; cin >> u >> v >> w;
        adj[u].pb({v,w}),adj[v].pb({u,w});        
    }

    rep1(i,n){
        dfs(i,-1,i,0);
    }

    vector<ll> cnt(n+5);
    rep1(u,n) cnt[u] = sz(good[u]);

    vector<bool> done(n+5);
    vector<ll> ans;
    // ll CNT = 5;

    while(true){
        pll best = {-1,-1};
        rep1(i,n){
            if(done[i]) conts;
            pll px = {cnt[i],i};
            amax(best,px);
        }

        if(best.ff == -1) break;

        ll u = best.ss;
        ans.pb(u);

        trav(v,good[u]){
            done[v] = 1;
            trav(w,good[v]){
                cnt[w]--;
            }
        }
    }

    cout << sz(ans) << endl;
    trav(x,ans) cout << x << " ";
    cout << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

• Subtask 1: 0 / 3
• Subtask 2: 0 / 5
• Subtask 3: 0 / 9
• Subtask 4: 0 / 19
• Subtask 5: 0 / 26
• Subtask 6: 0 / 38