Submission #921697

#	Time	Username	Problem	Language	Result	Execution time	Memory
921697		vjudge1	Lightning Rod (NOI18_lightningrod)	C++17	44 / 100	251 ms	616 KiB

Main

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
using namespace std;

void solve(){
    ll a,ans=0;
    cin>>a;
    if(a>2000){
        cout<<a;
        return ;
    }
    map<pair<ll,ll>,ll>mp;
    vector<pair<ll,ll> > v;
    for(ll i=1;i<=a;i++){
        ll x,y;
        cin>>x>>y;
        v.pb({y,x});
    }
    sort(v.begin(),v.end());
    reverse(v.begin(),v.end());
    if(v[0].second==v[v.size()-1].second){
        cout<<a;
        return ;
    }
    for(ll i=0;i<v.size();i++){
        for(ll j=0;j<v.size();j++){
            if(mp[v[j]]==0 && j!=i && mp[v[i]]==0){
                if(abs(v[i].second-v[j].second)<=v[i].first-v[j].first){
                    mp[v[j]]=1;
                    //cout<<v[j].first<<" "<<v[j].second<<"\n";
                }
            }
        }
    }    
    for(ll i=0;i<v.size();i++){
        if(mp[v[i]]==0){
            ans++;
        }
    }
    cout<<ans;
}

int main()
{
    ios_base::sync_with_stdio(0),cin.tie(0);
    ll t=1,i=1;
    //cin>>t;
    while(t--){
        //cout<<"Case ";
        //cout<<i<<':'<<"\n";
        //i++;
        solve();
    }
    return 0;
}

Compilation message (stderr)

lightningrod.cpp: In function 'void solve()':
lightningrod.cpp:26:17: 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]
   26 |     for(ll i=0;i<v.size();i++){
      |                ~^~~~~~~~~
lightningrod.cpp:27:21: 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]
   27 |         for(ll j=0;j<v.size();j++){
      |                    ~^~~~~~~~~
lightningrod.cpp:36:17: 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]
   36 |     for(ll i=0;i<v.size();i++){
      |                ~^~~~~~~~~
lightningrod.cpp: In function 'int main()':
lightningrod.cpp:47:12: warning: unused variable 'i' [-Wunused-variable]
   47 |     ll t=1,i=1;
      |            ^

• Subtask 1: 4 / 4
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 21 / 21
• Subtask 5: 0 / 26
• Subtask 6: 0 / 10
• Subtask 7: 0 / 20