Submission #924482

#	Time	Username	Problem	Language	Result	Execution time	Memory
924482		Sir_Ahmed_Imran	Railway (BOI17_railway)	C++17	100 / 100	135 ms	27380 KiB

railway

                              ///~~~LOTA~~~///
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define append push_back
#define add insert
#define nl "\n"
#define ff first
#define ss second
#define pii pair<int,int>
#define all(x) (x).begin(),(x).end()
#define L0TA ios_base::sync_with_stdio(false);cin.tie(NULL)
#define N 100001
int k;
int s[N];
vector<int> ans;
vector<pii> a[N];
vector<int> c[N];
map<int,int> *x[N];
void dfs(int v,int u){
    int z=0;
    for(auto& i:a[v]){
        if(i.ss==u) continue;
        dfs(i.ff,i.ss);
        if((*x[i.ff]).size()>(*x[z]).size())
            z=i.ff;
    }
    if(z>0) x[v]=x[z];
    else x[v]=new map<int,int>;
    for(auto &i:a[v]){
        if(i.ss==u || i.ff==z) 
            continue;
        for(auto& j:*x[i.ff]){
            (*x[v])[j.ff]+=j.ss;
            if(s[j.ff]==(*x[v])[j.ff])
                (*x[v]).erase(j.ff);
        }
        (*x[i.ff]).clear();
    }
    for(auto& i:c[v]){
        (*x[v])[i]++;
        if(s[i]==(*x[v])[i])
            (*x[v]).erase(i);
    }
    if((*x[v]).size()>=k)
        ans.append(u);
}
void solve(){
    int n,m,p,q;
    cin>>n>>m>>k;
    for(int i=1;i<n;i++){
        cin>>p>>q;
        a[p].append({q,i});
        a[q].append({p,i});
    }
    for(int i=0;i<m;i++){
        cin>>s[i];
        for(int j=0;j<s[i];j++){
            cin>>q;
            c[q].append(i);
        }
    }
    x[0]=new map<int,int>;
    dfs(1,0);
    sort(all(ans));
    cout<<ans.size()<<nl;
    for(auto& i:ans) cout<<i<<' ';
}
int main(){
    L0TA;
    solve();
    return 0;
}

Compilation message (stderr)

railway.cpp: In function 'void dfs(int, int)':
railway.cpp:45:22: warning: comparison of integer expressions of different signedness: 'std::map<int, int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   45 |     if((*x[v]).size()>=k)
      |        ~~~~~~~~~~~~~~^~~

• Subtask 1: 8 / 8
• Subtask 2: 15 / 15
• Subtask 3: 7 / 7
• Subtask 4: 29 / 29
• Subtask 5: 16 / 16
• Subtask 6: 25 / 25