Submission #699367

#	Time	Username	Problem	Language	Result	Execution time	Memory
699367		anhduc2701	Parkovi (COCI22_parkovi)	C++17	0 / 110	503 ms	59128 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){
    for(auto v:G[u]){
        if(v.fi==pa)continue;
        int w=v.se;
        dfs(v.fi,u,mid);
        f[u]=max(f[v.fi]-w,f[u]);
        dp[u]+=dp[v.fi];
        if(dist[v.fi]==0 && f[v.fi]>=0){
            mark[v.fi]=2;
            continue;
        }
        if(dist[v.fi]+w>mid){
            mark[v.fi]=1;
            f[u]=max(mid-w,f[u]);
            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(int mid){
    sum=0;
    for(int i=1;i<=n;i++){
        f[i]=-INF;
        dist[i]=0;
        mark[i]=0;
        dp[i]=0;
        res[i]=0;
    }
    dfs(1,-1,mid);
    
    dp[1]++;
    if(dist[1]==0 && f[1]>=0){
        dp[1]--;
    }
    else{
        mark[1]=1;
    }
    if(dp[1]<=k){
        return true;
    }
    else{
        return false;
    }
}
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 ans;
    
    while(l<=r){
        int mid=(l+r)/2;
        if(check(mid)){
            ans=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++){
        if(res[i]==1){
            cnt++;
        }
    }
    cnt=k-cnt;
    for(int i=1;i<=n;i++){
        if(res[i]==0 && cnt>0){
            res[i]=1;
            cnt--;
        }
    }
    cout<<ans<<"\n";
    for(int i=1;i<=n;i++){
        if(res[i]==1){
            cout<<i<<" ";
        }
    }
    return 0;
}

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