Submission #1086042

#	Time	Username	Problem	Language	Result	Execution time	Memory
1086042		hqminhuwu	Parkovi (COCI22_parkovi)	C++14	0 / 110	362 ms	31828 KiB

Main

#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair <ll,ll> pll;
typedef pair <ll,ll> pii;
typedef pair <ll,pii> piii;

#define forr(_a,_b,_c) for(ll _a = (_b); _a <= ll (_c); ++_a)
#define ford(_a,_b,_c) for(ll _a = (_b) + 1; _a --> ll (_c);)
#define forf(_a,_b,_c) for(ll _a = (_b); _a < ll (_c); ++_a)
#define st first
#define nd second
#define pb push_back
#define mp make_pair
#define all(x) begin(x),end(x)
#define mask(i) (1LL << (i))
#define bit(x, i) (((x) >> (i)) & 1)
#define bp __builtin_popcountll
#define file "test"

template<class X, class Y>
    bool minz(X &x, const Y &y) {
        if (x > y) {
            x = y;
            return true;
        } return false;
    }
template<class X, class Y>
    bool maxz(X &x, const Y &y) {
        if (x < y) {
            x = y;
            return true;
        } return false;
    }

const ll N = 5e5 + 5;
const ll oo = (ll) 2e16;
const ll mod = 1e9 + 7; // 998244353;

ll deg[N], n, u, v, w, k, cnt;
ll dist[N], park[N], flag[N];
priority_queue <pll, vector<pll>, greater<pll>> leaf;
ll rem[N];
vector <pll> a[N];
vector <ll> trace;

ll calcdist (ll u){
    dist[u] = -oo;
    flag[u] = 0;
    for (pll v : a[u]){
        if (rem[v.st]) flag[u] = 1;
        if (rem[v.st] && !(dist[v.st] < 0 && dist[v.st] + v.nd > 0)){
            dist[u] = max (dist[u], dist[v.st] + v.nd);
        }
    }
    if (dist[u] == -oo) dist[u] = 0;
    return dist[u];
}

ll solve(ll x){
    while (leaf.size()) leaf.pop();
    trace.clear();
    cnt = 0;

    forr (i, 1, n){
        rem[i] = 0;
        dist[i] = -2 * oo;
        deg[i] = a[i].size();
        if (a[i].size() == 1){
            leaf.push(mp(0, i));
        }
    }

    while (leaf.size()){
        ll u = leaf.top().nd;
        leaf.pop();
        if (rem[u]) continue;

        rem[u] = 1;
        dist[u] = -oo;
        cnt++;
        ll tmp = oo;

        calcdist(u);

        for (pll v : a[u]){
            if (rem[v.st]) continue;
            tmp = min (tmp, dist[u] + v.nd);
        }

      // cout << u << " " << tmp << " " << dist[u] << endl;

        for (pll v : a[u]){
            if (rem[v.st]) continue;
            deg[v.st]--;
            if (deg[v.st] == 1)
                leaf.push(mp(calcdist(v.st), v.st));
        }

        if (tmp == oo){
            ll ww = 0;
            for (pll v : a[u]){
                if (rem[v.st] && dist[u] + dist[v.st] + v.nd <= 0)
                    ww = 1;
            }

            if (ww) continue;
            //if (dist[u] > 0 || (dist[u] == 0 && !flag[u])){
            //    cout << u << ": " << endl;
                trace.pb(u);
                dist[u] = -x;
           // }
        } else
        if (tmp > x){
        //   cout << u << ": " << endl;
            trace.pb(u);
            dist[u] = -x;
        }
    }   

    return trace.size();
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    #ifdef hqm
        freopen(file".inp", "r", stdin); freopen(file".out", "w", stdout);
    #endif

    cin >> n >> k;

    forf (i, 1, n){
        cin >> u >> v >> w;
        a[u].pb({v, w});
        a[v].pb({u, w});
    }

    ll l = 0, r = oo;
   // l = 5, r = 5;

    while (l < r){
        ll mid = (l + r) >> 1;
        if (solve(mid) > k)
            l = mid + 1;
        else r = mid;
    }        

    
    solve(l);

    cout << l << "\n";


    for (ll u : trace){
        park[u] = 1;
    }

    k -= trace.size();

    forr (i, 1, n)
    if (!park[i] && k){
        k--;
        trace.pb(i);
    }

    //sort(all(trace));

    for (ll u : trace)
     //   cout << u << " ";
    
 
    return 0;
}
/*



*/

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:169:13: warning: unused variable 'u' [-Wunused-variable]
  169 |     for (ll u : trace)
      |             ^

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 60