Submission #1290346

#	Time	Username	Problem	Language	Result	Execution time	Memory
1290346		yonatanl	Lightning Rod (NOI18_lightningrod)	C++20	70 / 100	1018 ms	157600 KiB

Main

#include <iostream>
#include <vector>
#include <algorithm>
#include <set>

#define rep(i, s, e) for (ll i = s; i < e; i++)
#define upmax(a, b) a = max(a, b)
#define upmin(a, b) a = min(a, b)

using namespace std;
using ll = int;
using vll = vector<ll>;
using vvll = vector<vll>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;

void solve() {
	ll n;
	cin >> n;
	vpll p(n);
	rep(i, 0, n) cin >> p[i].first >> p[i].second;
	vll arr(n);
	vll arr2(n);
	rep(i, 0, n) {
		arr[i] = p[i].first - p[i].second;
		arr2[i] = p[i].first + p[i].second;
	}
	vector<bool> ans(n, true);
	ll mn = arr[n - 1];
	for (ll i = n - 2; i >= 0; i--) {
		if (arr[i] >= mn) {
			ans[i] = false;
		}
		else mn = arr[i];
	}
	ll mx = arr2[0];
	rep(i, 1, n) {
		if (arr2[i] <= mx) {
			ans[i] = false;
		}
		else mx = arr2[i];
	}
	ll res = 0;
	rep(i, 0, n) if (ans[i]) res++;
	cout << res << '\n';
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);

	solve();
}

• Subtask 1: 4 / 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