Submission #733898

#	Time	Username	Problem	Language	Result	Execution time	Memory
733898		vjudge1	Lightning Rod (NOI18_lightningrod)	C++17	44 / 100	2035 ms	144084 KiB

Main

#include<bits/stdc++.h>

using namespace std;
using ll = long long;
int main() {
	int t, n, m, ans, i, z,j, x, r, p, s, y;
	
	cin >> n;
	vector < pair < int, int > > v;
	ans = 0;
	r= 1e9;
	p = -1e9;
	s = 0;
	for ( i = 1; i <= n; i ++) {
		scanf("%d",& x);
		scanf("%d",& y);
		if ( x == i) s ++;
		v.push_back(make_pair(2 * y, x - y));
		p = max (p, y);
		r = min(r, y);
	}
	if ( r == 1 && p == 1) {
		cout << n << endl;
		return 0;
	}
	if ( r == 0 && p == 1 && s == n) {
		vector < int > q;
		for ( i = 1; i <= n; i ++) {
			q.push_back(v[i].first/2);
		}
		ans = 1;
		for ( j = 0; j < q.size() - 1; j ++) {
			if ( q[j] == q[j + 1]) ans ++;
		}
		cout << ans << endl;
		return 0;
	}
	sort ( v.begin(), v.end());
	for ( i = v.size() - 1; i >= 0; i -- ) {
		ans ++;
		
		for ( j = i + 1; j < v.size(); j ++) {
			if ( v[j].second <= v[i].second && (v[j].second + v[j].first) >= (v[i].second + v[i].first)) {
				ans --;
				break;
			}			
		}
	}
	cout << ans << endl;
}

Compilation message (stderr)

lightningrod.cpp: In function 'int main()':
lightningrod.cpp:32:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |   for ( j = 0; j < q.size() - 1; j ++) {
      |                ~~^~~~~~~~~~~~~~
lightningrod.cpp:42:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |   for ( j = i + 1; j < v.size(); j ++) {
      |                    ~~^~~~~~~~~~
lightningrod.cpp:6:6: warning: unused variable 't' [-Wunused-variable]
    6 |  int t, n, m, ans, i, z,j, x, r, p, s, y;
      |      ^
lightningrod.cpp:6:12: warning: unused variable 'm' [-Wunused-variable]
    6 |  int t, n, m, ans, i, z,j, x, r, p, s, y;
      |            ^
lightningrod.cpp:6:23: warning: unused variable 'z' [-Wunused-variable]
    6 |  int t, n, m, ans, i, z,j, x, r, p, s, y;
      |                       ^
lightningrod.cpp:15:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |   scanf("%d",& x);
      |   ~~~~~^~~~~~~~~~
lightningrod.cpp:16:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |   scanf("%d",& y);
      |   ~~~~~^~~~~~~~~~

• Subtask 1: 4 / 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