Submission #949945

#	Time	Username	Problem	Language	Result	Execution time	Memory
949945		sondos225	Firefighting (NOI20_firefighting)	C++17	0 / 100	270 ms	34860 KiB

Firefighting

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T>using ordered_set = tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;//find_by_order(ind);
//order_of_key()
#define int long long
#define fast ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
#define pb push_back
#define yes "YES"
#define no "NO"
#define bigg INT_MAX
#define debug(x) cout<<(#x)<<" = " <<x<<endl;
#define all(x) x.begin(),x.end()
#define sz size()
#define nn '\n'
#define mms(x,y) memset(x,y,sizeof(x))
#define forr(i,j,n) for (int i=j; i<n; i++)
#define forn(i,j,n) for (int i=j; i>n; i--)
#define fi first
#define se second
#define la "LA"
#define cinn(x,y) for(int i=0; i<y; i++) cin>>x[i];
#define pii pair<int,int>
vector<pii> a[300001];
priority_queue<pii> q;
bool vis[300001]={ };
void dfs(int x, int cover)
{
    //cout<<"HA"<<x<<' '<<cover<<endl;
    vis[x]=1;
    for(auto y:a[x])
    {
        if (vis[y.fi]) continue;
        if (cover>=y.se)
        {
            dfs(y.fi,cover-y.se);
        }
        else
        {
            q.push({0,y.fi});
         //   cout<<"NOOOOO"<<y.fi<<endl;
        }
    }
    return;
}
signed main()
{
//    #ifndef LOCAL
//    freopen("lifeguards.in","r",stdin);
//    freopen("lifeguards.out","w", stdout);
//    #endif
    fast
    int n,k;
    cin>>n >>k;
    forr(i,0,n-1)
    {
        int x,y,z;
        cin>>x >>y >>z;
        a[x].pb({y,z});
        a[y].pb({x,z});
    }

    forr(i,1,n+1)
    {
        if (a[i].sz==1) q.push({0,i});
    }
    vector<int> ans;
    while(!q.empty())
    {

        int last=q.top().fi;
        int x=q.top().se;
        q.pop();
        if (vis[x]) continue;
        //cout<<x<<' '<<last<<endl;
        vis[x]=1;
        int mx=0;
        int f=-1;
        for(auto w:a[x])
        {
            int y=w.fi;
            int z=w.se;
            if (vis[y]) continue;
            if (z>k) {
                    f=0;
                    //cout<<la<<x<<' '<<y<<endl;
            q.push({0,y});}
            else if ((z+last)>k)
            {
              mx=max(mx,z);
              f=1;
            }
            else
            {
               f=1;
            }
        }
        if (f==-1)
        {
            ans.pb(x);
        }
        else if (f==0)
        {
            ans.pb(x);
        }
        else if (mx==0)
        {
            for(auto w:a[x])
        {
            int y=w.fi;
            int z=w.se;
            if(vis[y]) continue;
            if (z<=k) q.push({z+last,y});
        }
        }
        else
        {
            ans.pb(x);
            for(auto w:a[x])
        {
            int y=w.fi;
            int z=w.se;
            if (vis[y]) continue;
            if (z<=k)
            {
               // cout<<y<<endl;
                dfs(y,k-z);
              //  int cur=y;
              //  while()
            }
        }
        }
    }
  //  if (ans.sz==0) {cout<<1<<nn<<1; return 0;}
    cout<<ans.sz<<nn;
    for(auto p:ans) cout<<p<<' ';
    return 0;
}

• Subtask 1: 0 / 3
• Subtask 2: 0 / 5
• Subtask 3: 0 / 9
• Subtask 4: 0 / 19
• Subtask 5: 0 / 26
• Subtask 6: 0 / 38