제출 #1290350

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1290350		yonatanl	Lightning Rod (NOI18_lightningrod)	C++20	100 / 100	431 ms	234360 KiB

Main

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

#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>;

inline int readInt() {
	int x = 0; char ch = getchar_unlocked(); bool s = 1;
	while (ch < '0' || ch>'9') { if (ch == '-')s = 0; ch = getchar_unlocked(); }
	while (ch >= '0' && ch <= '9') { x = (x << 3) + (x << 1) + ch - '0'; ch = getchar_unlocked(); }
	return s ? x : -x;
}

void solve() {
	ll n;
	n = readInt();
	vpll p(n);
	rep(i, 0, n) {
		p[i].first = readInt();
		p[i].second = readInt();
	}
	vpll arr(n);
	rep(i, 0, n) {
		arr[i].first = p[i].first - p[i].second;
		arr[i].second = p[i].first + p[i].second;
	}
	vpll pref(n);
	pref[n - 1].first = arr[n - 1].first;
	pref[0].second = arr[0].second;
	rep(i, 1, n) pref[i].second = max(pref[i - 1].second, arr[i].second);
	for (ll i = n - 2; i >= 0; i--) pref[i].first = min(pref[i + 1].first, arr[i].first);
	ll ans = n;
	rep(i, 0, n) {
		if ((i < n - 1 && pref[i + 1].first <= arr[i].first) || (i > 0 && pref[i - 1].second >= arr[i].second)) {
			ans--;
		}
	}
	cout << ans << '\n';
	/*
	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: 10 / 10
• Subtask 7: 20 / 20