Submission #1114642

#	Time	Username	Problem	Language	Result	Execution time	Memory
1114642		kokoue	Bitaro’s Party (JOI18_bitaro)	C++14	100 / 100	815 ms	216144 KiB

bitaro

#include<bits/stdc++.h>
#define maxn 100010
#define f first
#define s second
#define ll long long
using namespace std;
ll n,m,q;
vector<ll> edges[maxn];
bool blocked[maxn];
int main()
{
 
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
 
    cin>>n>>m>>q;
 
    for(ll i=0;i<m;i++)
    {
        ll a,b;
        cin>>a>>b;
        if(a<b) swap(a,b);
        edges[a].push_back(b);
    }
    ll B=100;
    vector<pair<ll,ll>> longest[n+1];
    vector<ll> dist(n+1,-1);
    for(ll i=1;i<=n;i++)
    {
       // longest[i].push_back({0,i});
        vector<ll> from;
        vector<pair<ll,ll>> curr;
        curr.push_back({0,i});
       for(auto e:edges[i])
        {
            for(auto fff:longest[e])
            {
                ll way=fff.f;
                ll ver=fff.s;
                if(dist[ver]==-1)
                {
                    from.push_back(ver);
                    dist[ver]=way+1;
 
                }
                else dist[ver]=max(dist[ver],way+1);
            }
        }
        for(auto e:from) curr.push_back({dist[e],e});
        sort(curr.begin(),curr.end());
        reverse(curr.begin(),curr.end());
        ll idx=0;
 
        while(idx<B && idx<curr.size())
        {
            longest[i].push_back({curr[idx].f,curr[idx].s});
            idx++;
        }
 
        for(auto e:from) dist[e]=-1;
 
        from.clear();
        curr.clear();
    }
    for(ll i=0;i<q;i++)
    {
        ll start,y;
        cin>>start>>y;
        vector<ll> c(y);
        for(ll j=0;j<y;j++)
        {
            cin>>c[j];
            blocked[c[j]]=1;
        }
        ll ans=-1;
        if(y>=B-1)
        {
           vector<ll> dp(start+1,-INT_MAX);
           dp[start]=0;
           for(ll j=start;j>0;j--)
           {
               if(dp[j]==-INT_MAX) continue;
               if(!blocked[j]) ans=max(ans,dp[j]);
               for(auto e:edges[j]) dp[e]=max(dp[e],dp[j]+1);
           }
        }
        if(y<B-1)
        {
            for(ll j=0;j<longest[start].size();j++)
            {
                if(!blocked[longest[start][j].s]) {ans=longest[start][j].f;break;}
            }
        }
        cout<<ans<<"\n";
        for(auto e:c) blocked[e]=0;
    }
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:55:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |         while(idx<B && idx<curr.size())
      |                        ~~~^~~~~~~~~~~~
bitaro.cpp:90:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   90 |             for(ll j=0;j<longest[start].size();j++)
      |                        ~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 86 / 86