Submission #1186327

#	Time	Username	Problem	Language	Result	Execution time	Memory
1186327		dosts	Parkovi (COCI22_parkovi)	C++17	0 / 110	161 ms	61768 KiB

Main

#include <bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define vi vector<int>
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
#define sp << " " << 
using namespace std;

const int N = 2e5+10,MOD = 998244353,inf = 2e12;
int n,k;
vector<pii> edges[N];
int up[N][20];
vi d(N);
vi leaves;
void dfs(int node,int p,int der = 0) {
    if (node > 1 && edges[node].size() == 1) leaves.push_back(node);
    up[node][0] = p;
    d[node] = der;
    for (int i = 1;i<20;i++) up[node][i] = up[up[node][i-1]][i-1];
    for (auto it : edges[node]) {
        if (it.ff == p) continue;
        dfs(it.ff,node,der+it.ss);
    }
} 

vi active(N,1),usedd(N,0);
vi anss;

int find(int node,int k) {
    int cur = node;
    for (int i = 19;i>=0;i--) {
        if (d[node]-d[up[cur][i]] <= k && active[up[cur][i]]) cur = up[cur][i];
    }
    return cur;
}
bool check(int dep,bool construct = 0) {
    active.assign(n+1,1);
    int used = 0;
    priority_queue<pii> pq;
    for (auto it : leaves) {
        int gogo = find(it,dep);
        pq.push({d[gogo],gogo});
    }
    while (!pq.empty()) {
        int f = pq.top().ss;
        pq.pop();
        if (!active[f]) continue;
        if (construct) anss.push_back(f),usedd[f] = 1;
        used++;
        queue<pii> q;
        q.push({f,0});
        active[f] = 0;
        while (!q.empty()) {
            int tp = q.front().ff,c = q.front().ss;
            q.pop();
            for (auto it : edges[tp]) {
                if (it.ss+c > dep) continue;
                if (!active[it.ff]) continue;
                active[it.ff] = 0;
                q.push({it.ff,c+it.ss});
            }
        }
        int gogo = find(f,dep);
        if (d[f]-d[up[gogo][0]] > dep) pq.push({d[up[gogo][0]],up[gogo][0]});
    }
    if (construct) {
        for (int i=1;i<=n;i++) {
            if (!usedd[i] && anss.size() < k) anss.push_back(i);
        }
    }
    return used <= k;
}

void solve() {
    cin >> n >> k;
    for (int i=1;i<n;i++) {
        int a,b,w;
        cin >> a >> b >> w;
        edges[a].push_back({b,w});
        edges[b].push_back({a,w});
    }    
    dfs(1,1);
    int l = 0;
    int r = 1e15;
    while (l<=r) {
        int m = (l+r) >> 1;
        if (check(m)) r = m-1;
        else l = m+1;
    }
    cout << l << '\n';
    check(l,1);
    sort(all(anss));
    for (auto it : anss) cout << it << ' ';
    cout << '\n';
}

signed main() {
    ios_base::sync_with_stdio(0);cin.tie(0);
    #ifdef Dodi
        freopen("in.txt","r",stdin);
        freopen("out.txt","w",stdout);
    #endif
    int t = 1;
    //cin >> t;
    while (t --> 0) solve();
} 

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