Submission #547188

#	Time	Username	Problem	Language	Result	Execution time	Memory
547188		Ahmed57	Lightning Rod (NOI18_lightningrod)	C++14	66 / 100	1450 ms	262144 KiB

Main

#include<bits/stdc++.h>
using namespace std;


int main() {
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    long long n;cin>>n;
    vector<pair<long long,long long>> v;
    for(int i = 0;i<n;i++){
        long long a,b;
        cin>>a>>b;
        v.push_back({a,b});
    }
    long long per[n]={} , suf[n]={};
    per[0] = v[0].first+v[0].second;
    suf[n-1] = v[n-1].second-v[n-1].first;
    for(int i = 1;i<n;i++){
        per[i] = max(per[i-1],v[i].first+v[i].second);
    }for(int i = n-2;i>=0;i--){
        suf[i] = max(suf[i+1],v[i].second-v[i].first);
    }
    long long ans = 0;
    for(int i = 0;i<n;i++){
        if(i==0){
            if(suf[i+1]<v[i].second-v[i].first){
                ans++;
            }
        }else if(i==n-1){
            if(per[i-1]<v[i].first+v[i].second)ans++;
        }else{
            if(suf[i+1]<v[i].second-v[i].first&&per[i-1]<v[i].first+v[i].second)ans++;
        }
    }
    cout<<ans<<"\n";
	return 0;
}

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