Submission #417980

#	Time	Username	Problem	Language	Result	Execution time	Memory
417980		gromperen	Lightning Rod (NOI18_lightningrod)	C++14	70 / 100	2057 ms	262144 KiB

Main

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

#define ll long long


int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);

	int n; cin >> n;
	int ans = 0;
	vector<int>x(n), y(n);
	for (int i = 0; i < n; ++i) {
		cin >> x[i] >> y[i];
	}

	vector<int> pre(n),suf(n);
	for (int i = 0; i < n; ++i) {
		pre[i] = x[i] + y[i];
		if (i > 0) pre[i] = max(pre[i-1], pre[i]);
	}
	for (int i = n-1; i >= 0; --i) {
		suf[i] = y[i] - x[i];
		if (i < n-1) suf[i] = max(suf[i+1],suf[i]);
	}
	for (int i = 0; i < n; ++i) {
		if (((i == 0) || pre[i] > pre[i-1]) && ((i == n-1) || suf[i] > suf[i+1])) {
			ans++;
		}
	}
	cout << ans << "\n";



	return 0;
}

• 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