Submission #123094

#	Time	Username	Problem	Language	Result	Execution time	Memory
123094		mechfrog88	Lightning Rod (NOI18_lightningrod)	C++14	0 / 100	2066 ms	161076 KiB

Main

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize("unroll-loops,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
using namespace __gnu_pbds;
using namespace std;
 
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
typedef long long ll;
typedef long double ld;	

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	ll n;
	scanf("%lld",&n);
	vector <pair<ll,ll>> arr(n);
	for (int z=0;z<n;z++){
		scanf("%lld %lld",&arr[z].first,&arr[z].second);
		arr[z].first -= arr[z].second;
		arr[z].second += arr[z].first;
	}
	stack <pair<ll,ll>> s;
	for (int z=0;z<n;z++){
		if (s.empty()){
			s.push(arr[z]);
		}
		if (s.top().first <= arr[z].first && arr[z].second <= s.top().second) continue;
		else{
			while (arr[z].first <= s.top().first && s.top().second <= arr[z].second){
				s.pop();
				if (s.size() == 0) break;
			}
			s.push(arr[z]);
		}
	}
	printf("%lld",ll(s.size()));
}

Compilation message (stderr)

lightningrod.cpp: In function 'int main()':
lightningrod.cpp:20:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld",&n);
  ~~~~~^~~~~~~~~~~
lightningrod.cpp:23:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld %lld",&arr[z].first,&arr[z].second);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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