oj.uz

답안 #119669

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
119669 2019-06-21T16:53:15 Z tmwilliamlin168 Printed Circuit Board (CEOI12_circuit) C++14
70 / 100
 46 ms 4852 KB 
#include <bits/stdc++.h>
using namespace std;

#define ll long long

const int mxN=2e5;
int n, l, r;
ll x[mxN+1], y[mxN+1];
vector<int> v, s;
bool b[mxN];

ll cp(int a, int b, int c) {
	return (y[c]-y[a])*(x[b]-x[a])-(y[b]-y[a])*(x[c]-x[a]);
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n;
	for(int i=0; i<n; ++i) {
		cin >> x[i] >> y[i];
		if(!i||cp(n, l, i)>0||!cp(n, l, i)&&x[i]<x[l])
			l=i;
		if(!i||cp(n, r, i)<0||!cp(n, r, i)&&x[i]<x[r])
			r=i;
	}
	//cout << l << " " << r << endl;
	int ic=cp((l+n-1)%n, l, (l+1)%n)>0?1:n-1;
	for(; l^r; l=(l+ic)%n)
		v.push_back(l);
	v.push_back(r);
	//cout << "a" << endl;
	//for(int i : v)
		//cout << x[i] << " " << y[i] << endl;
	s={0, 1};
	for(int i=2; i<v.size(); ++i) {
		//cout << i << endl;
		//for(int si : s)
			//cout << si << " ";
		//cout << endl;
		if(cp(n, v[i-1], v[i])<0) {
			if((cp(n, v[s.back()-1], v[s.back()])<=0||cp(v[s.back()-1], v[s.back()], v[i])>0)&&cp(n, v[s.back()], v[i])<0)
				s.push_back(i);
		} else {
			if(s.back()==i-1) {
				if(cp(n, v[i-2], v[i-1])<0?cp(v[i-2], v[i-1], v[i])>0:!cp(n, v[i-1], v[i])&&cp(v[i-2], v[i-1], v[i])<0)
					continue;
				s.pop_back();
			} else if(s.back()&&cp(n, v[s.back()-1], v[s.back()])>=0) {
				if(cp(n, v[s.back()], v[i])<=0)
					continue;
				s.pop_back();
			}
			while(cp(n, v[i], v[s.back()])<=0&&cp(n, v[s.back()], v[i-1])<0&&cp(v[i], v[i-1], v[s.back()])>0)
				s.pop_back();
			if(cp(n, v[i], v[s.back()])>0)
				s.push_back(i);
		}
	}
	cout << s.size() << "\n";
	for(int a : s)
		b[v[a]]=1;
	for(int i=0; i<n; ++i)
		if(b[i])
			cout << i+1 << " ";
}

Compilation message

circuit.cpp: In function 'int main()':
circuit.cpp:23:37: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(!i||cp(n, l, i)>0||!cp(n, l, i)&&x[i]<x[l])
                         ~~~~~~~~~~~~^~~~~~~~~~~
circuit.cpp:25:37: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(!i||cp(n, r, i)<0||!cp(n, r, i)&&x[i]<x[r])
                         ~~~~~~~~~~~~^~~~~~~~~~~
circuit.cpp:37:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=2; i<v.size(); ++i) {
               ~^~~~~~~~~

Subtask #1
70.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 384 KB Output is correct
2 Incorrect 2 ms 384 KB Output isn't correct
3 Correct 2 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct
5 Correct 5 ms 640 KB Output is correct
6 Correct 6 ms 640 KB Output is correct
7 Correct 8 ms 896 KB Output is correct
8 Correct 4 ms 640 KB Output is correct
9 Correct 4 ms 640 KB Output is correct
10 Correct 4 ms 640 KB Output is correct
11 Correct 5 ms 768 KB Output is correct
12 Correct 7 ms 1024 KB Output is correct
13 Correct 9 ms 1152 KB Output is correct
14 Incorrect 9 ms 1280 KB Output isn't correct
15 Incorrect 12 ms 1664 KB Output isn't correct
16 Incorrect 21 ms 2680 KB Output isn't correct
17 Correct 23 ms 2424 KB Output is correct
18 Incorrect 41 ms 4852 KB Output isn't correct
19 Incorrect 41 ms 4852 KB Output isn't correct
20 Correct 46 ms 4852 KB Output is correct