Submission #1040155

#	Time	Username	Problem	Language	Result	Execution time	Memory
1040155		Marco_Escandon	Event Hopping (BOI22_events)	C++11	10 / 100	1602 ms	43448 KiB

events

#include<bits/stdc++.h>
using namespace std;
typedef int ll;
#define x first
#define y second
#pragma optimize("O3")
vector<vector<ll>> G( 5005);
vector<ll> v[5005];
vector<pair<ll,ll>> input;
void cmc(ll n,ll ini)
{
    v[ini].assign(n+1,1e9);
    queue<ll> q;
    q.push(ini);
    v[ini][ini]=0;
    map<ll,ll> mapa;
    while(!q.empty())
    {
        ll a=q.front();q.pop();
        for(auto i:G[a])
        {
            if(v[ini][i]==1e9)
            {
                v[ini][i]=v[ini][a]+1;
                if(mapa[input[i].y]==0)
                {
                    q.push(i);
                    mapa[input[i].y]=1;
                }
            }
        }
    }
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    ll n,q;
    cin>>n>>q;
    input.push_back({0,0});
    vector<pair<ll,ll>> cad;
    for(int i=1; i<=n; i++)
    {
        ll a,b;
        cin>>a>>b;
        input.push_back({a,b});
        cad.push_back({a,i});
        cad.push_back({b,i});
    }
    sort(cad.begin(),cad.end());
    set<ll> s;
    for(int i=0; i<cad.size(); i++)
    {
        vector<ll> temp,temp2;
        ll a=i;
        while(i<cad.size()&&cad[a].x==cad[i].x){
            temp.push_back(cad[i].y);
            i++;
        }
        i--;
        for(auto j:temp)
        {
            if(s.find(j)!=s.end())
                temp2.push_back(j);
            else s.insert(j);
        }
        for(auto j:temp2) for(auto k:s) G[j].push_back(k);
        for(auto j:temp2) if(s.find(j)!=s.end()) s.erase(j);
    }
    for(int i=1; i<=n; i++)
        cmc(n,i);
    for(int i=0; i<q; i++)
    {
        ll a,b;
        cin>>a>>b;
        a=v[a][b];
        if(a==1e9) cout<<"impossible"<<"\n";
        else cout<<a<<"\n";
    }
    return 0;
}

Compilation message (stderr)

events.cpp:6: warning: ignoring '#pragma optimize ' [-Wunknown-pragmas]
    6 | #pragma optimize("O3")
      | 
events.cpp: In function 'int main()':
events.cpp:52:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |     for(int i=0; i<cad.size(); i++)
      |                  ~^~~~~~~~~~~
events.cpp:56:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |         while(i<cad.size()&&cad[a].x==cad[i].x){
      |               ~^~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30