Submission #1166718

#	Time	Username	Problem	Language	Result	Execution time	Memory
1166718		shidou26	Lightning Rod (NOI18_lightningrod)	C++20	40 / 100	1098 ms	78412 KiB

Main

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

#define endl '\n'
#define sz(v) (int)v.size()
#define all(v) v.begin(), v.end()
#define filter(v) v.resize(unique(all(v)) - v.begin())
#define dbg(v) "[" #v " = " << (v) << "]"

template<typename T> bool maximize(T &a, T b) {
	if(a < b) {
		a = b;
		return true;
	}else return false;
}
template<typename T> bool minimize(T &a, T b) {
	if(a > b) {
		a = b;
		return true;
	}else return false;
}

typedef long long ll;
typedef long double ld;

const int N = 1e7 + 3;

int n;
pair<int, int> rods[N];

bool mark[N];

void process() {
	sort(rods + 1, rods + 1 + n, [](pair<int, int> a, pair<int, int> b){
		return (a.second == b.second ? a.first < b.first : a.second > b.second);
	});

	for(int i = 1; i <= n; i++) {
		mark[i] = true;
		for(int j = 1; j < i; j++) if(mark[j] && abs(rods[i].first - rods[j].first) <= rods[j].second - rods[i].second) {
			mark[i] = false;
			break;
		} 
	}

	int answer = 0;
	for(int i = 1; i <= n; i++) answer += mark[i];
	cout << answer << endl;
}

void input() {
	cin >> n;

	for(int i = 1; i <= n; i++) {
		cin >> rods[i].first >> rods[i].second;
	}	
}

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

	#define task "DateALive"
	if(fopen(task".INP", "r")) {
		freopen(task".INP", "r", stdin);
		freopen(task".OUT", "w", stdout);
	}

	int testcase = 1; // cin >> testcase;
	for(int i = 1; i <= testcase; i++) {
		input();
		process();
	}
	
	return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:65:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |                 freopen(task".INP", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:66:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |                 freopen(task".OUT", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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