Submission #921643

#	Time	Username	Problem	Language	Result	Execution time	Memory
921643		vjudge1	Lightning Rod (NOI18_lightningrod)	C++17	40 / 100	855 ms	262144 KiB

Main

#include <bits/stdc++.h>
#include <iomanip>
#define ll long long
#define int long long
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define str string
#define pii pair<int,int>
#define sz(x) x.size()
#define all(x) x.begin(), x.end()
#define vi vector<int>
#define mii map<int,int>
#define mll map<ll,ll>
#define yes cout<<"YES\n";
#define no cout<<"NO\n";
#define yess cout<<"Yes\n";
#define noo cout<<"No\n";
using namespace std;

#define maxn 1111111
#define mod  1000000007

int u[10000001];

void solve(){
    int n;
    cin>>n;
    pair<int,int>a[n+3];
    set<int>s;
    for(int i=1;i<=n;i++){
        cin>>a[i].ss>>a[i].ff;
        s.insert(a[i].ss);
    }
    if(n>2000){
        cout<<s.size();
        return;
    }
    sort(a+1,a+1+n);
    for(int i=n;i>=2;i--){
        if(u[i]==1){
            continue;
        }
        for(int j=i-1;j>=1;j--){
            //cout<<(abs(a[i].ss-a[j].ss)<=a[i].ff-a[j].ff)<<" "<<a[i].ss<<" "<<a[j].ss<<" "<<a[i].ff<<" "<<a[j].ff<<"\n";
            if(abs(a[i].ss-a[j].ss)<=a[i].ff-a[j].ff){
                u[j]=1;
            }
        }
    }
    int ans=0;
    for(int i=1;i<=n;i++){
        ans+=(u[i]==0);
    }
    cout<<ans;
}

signed main(){
	ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	//srand( time(0));
	//freopen("sum.in", "r", stdin);
	//freopen("sum.out", "w", stdout);
    int tests=1;
    //cin>>tests;
    for(int i=1;i<=tests;i++){
		//cout<<"Case "<<i<<": \n";
		solve();
	}
}

• Subtask 1: 0 / 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