Submission #825951

#	Time	Username	Problem	Language	Result	Execution time	Memory
825951		karrigan	Parkovi (COCI22_parkovi)	C++14	110 / 110	1985 ms	36332 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define all(fl) fl.begin(),fl.end()
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define lb lower_bound
#define ub upper_bound
#define sz(a) (int)a.size()
#define pii pair<int,int>
#define pli pair<long long,int>
#define pil pair<int,long long>
#define gcd __gcd
#define lcm(x,y) x*y/__gcd(x,y)
const int maxn=2e5+9;
const long long inf=1e15;
vector<pil>a[maxn];
int n,k;
struct ver{
long long maxdis;
int num;
long long mindis;
ver (){
maxdis=0;
num=0;
mindis=inf;
}
}b[maxn];
vector<int>take;
void dfs(int u,int par,long long mid){
//cerr<<u<<'\n';
if (sz(a[u])==1&&a[u][0].fi==par){
    //cerr<<u<<'\n';
    for (auto v:a[u]){
        if (v.se>mid){
            b[u].mindis=0;
            b[u].maxdis=-1;
          	take.pb(u);
            b[u].num=1;
        }
        else {
            b[u].maxdis=v.se;
        }
    }
    return;
}
for (auto v:a[u]){
    if (v.fi==par)continue;
    dfs(v.fi,u,mid);
    b[u].maxdis=max(b[u].maxdis,b[v.fi].maxdis);
    b[u].num+=b[v.fi].num;
    b[u].mindis=min(b[u].mindis,b[v.fi].mindis+v.se);
}
if (b[u].mindis+b[u].maxdis<=mid){
   b[u].maxdis=-1;
}
//if (u==8)cout<<b[u].mindis<<" "<<b[u].maxdis<<'\n';
for (auto v:a[u]){
    if (v.fi==par){
        if (b[u].maxdis==-1){
            continue;
        }
        if (b[u].maxdis+v.se>mid){
            b[u].num++;
          	take.pb(u);
            //cerr<<u<<'\n';
            b[u].mindis=0;
            b[u].maxdis=-1;
        }
        else {
            b[u].maxdis+=v.se;
        }
    }
}
if (u==1){
    if (b[u].maxdis!=-1){
        b[u].num++;
      	take.pb(u);
        //cerr<<u<<'\n';
    }
}
}
bool check(long long mid){
take.clear();
for1(i,1,n){
b[i]=ver();
}
//cerr<<b[8].num<<'\n';
dfs(1,0,mid);
if (b[1].num>k)return false;
return true;
}
bool vis[maxn];
void push(){
  for (auto v:take )vis[v]=1;
  for1(i,1,n){
    if (vis[i])continue;
    if (sz(take)==k)return;
    take.pb(i);
    vis[i]=1;
  }
  
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen("KTREE.INP","r",stdin);
    //freopen("KTREE.OUT","w",stdout);
    cin>>n>>k;
    for1(i,1,n-1){
    int u,v;
    long long w;
    cin>>u>>v>>w;
    a[u].pb({v,w});
    a[v].pb({u,w});
    }
    long long l=0,r=2e14,ans=2e14;
    while (l<=r){
        long long mid=(l+r)/2;
        if (check(mid)){
            r=mid-1;
            ans=mid;
        }
        else l=mid+1;
    }
    cout<<ans<<'\n';
  	check(ans);
  	push();
   for (auto v:take)cout<<v<<" ";
    //cout<<check(7);
}

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