Submission #699372

#	Time	Username	Problem	Language	Result	Execution time	Memory
699372		anhduc2701	Parkovi (COCI22_parkovi)	C++17	110 / 110	1952 ms	64076 KiB

Main

/*
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("unroll-loops")
*/
#include<bits/stdc++.h>
#define int long long
using namespace std;
#define all(x) x.begin(), x.end()
#define len(x) ll(x.size())
#define eb emplace_back
#define PI 3.14159265359
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define MIN(v) *min_element(all(v))
#define MAX(v) *max_element(all(v))
#define BIT(x,i) (1&((x)>>(i)))
#define MASK(x) (1LL<<(x))
#define task "tnc"  
typedef long long ll;
const ll INF=1e18;
const int maxn=1e6+5;
const int mod=1e9+7;
const int mo=998244353;
using pi=pair<ll,ll>;
using vi=vector<ll>;
using pii=pair<pair<ll,ll>,ll>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int n,k;
int res[maxn];
vector<pair<int,int>>G[maxn];
int sum=0;
int f[maxn];
int dist[maxn];
int mark[maxn];
int dp[maxn];
void dfs(int u,int pa,int mid){
     mark[u] = 0, dp[u] = 0, f[u] = -INF, dist[u] = 0;
     for(int i=0; i<(int)G[u].size(); ++i)
    {
        int v = G[u][i].fi;
        if(v == pa) continue;
        dfs(v, u, mid);
        int w = G[u][i].se;
        f[u] = max(f[u], f[v] - w);
        dp[u] += dp[v];
        if(dist[v] == 0 && f[v] >= 0)
        {
            mark[v] = 2;
            continue;
        }
        if(dist[v] + w > mid)
        {
            mark[v] = 1;
            f[u] = max(f[u], mid - w);
            dp[u]++;
        }
    }
    for(auto v:G[u]){
        if(v.fi==pa || mark[v.fi])continue;
        if(f[u]-v.se>=dist[v.fi]){
            mark[v.fi]=2;
        }
    }
    for(auto v:G[u]){
        if(v.fi==pa || mark[v.fi])continue;
        dist[u]=max(dist[u],dist[v.fi]+v.se);
    }
}
bool check(long long mid)
{
    dfs(1, -1, mid);
    dp[1]++;
    if(dist[1] == 0 && f[1] >= 0)
        --dp[1];
    return (dp[1] <= k);
}

signed main()
{
	cin.tie(0),cout.tie(0)->sync_with_stdio(0);
    //freopen(task".inp" , "r" , stdin);
    //freopen(task".out" , "w" , stdout);
    cin>>n>>k;

    int l,r;
    l=0;
    for(int i=1;i<n;i++){
        int x,y,w;
        cin>>x>>y>>w;
        G[x].pb({y,w});
        G[y].pb({x,w});
    }
    r=1e15;
    int best;
    while(l <= r)
    {
        long long mid = (l+r)/2;
        if(check(mid))
        {
            best = mid;
            for(int i=1; i<=n; ++i)
                if(mark[i] == 1) res[i] = 1;
                else res[i] = 0;
            r = mid - 1;
        }
        else l = mid + 1;
    }
    int cnt = 0;
    for(int i=1; i<=n; ++i) 
        cnt += res[i];
    cnt = k - cnt;
    for(int i=1; i<=n; ++i)
        if(res[i] == 0 && cnt > 0)
            res[i] = 1, --cnt;
    cout << best << '\n';
     for(int i=1; i<=n; ++i)
         if(res[i]) cout << i << " ";
    return 0;
}

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