Submission #167094

# Submission time Handle Problem Language Result Execution time Memory
167094 2019-12-05T14:37:07 Z cgiosy None (KOI18_footprint) C++17
55 / 100
44 ms 1912 KB
#include <bits/stdc++.h>
#define rep(i,x,n) for(int i=x; i<n; i++)
using namespace std;

struct pii {
	int x, y;
	bool operator<(const pii b) const { return y<b.y || (y==b.y && x<b.x); }
	pii operator-(const pii b) const { return {x-b.x, y-b.y}; }
};
long cross(pii a, pii b) { return a.x*long(b.y)-a.y*long(b.x); }
long ccw(pii o, pii a, pii b) { return cross(o-a, o-b); }
int main() {
	ios_base::sync_with_stdio(false);cin.tie(nullptr);
	int N;
	cin>>N;
	vector<pii> A(N);
	for(auto&[x,y]:A) cin>>x>>y;
	swap(A[0], *min_element(begin(A), end(A)));
	sort(begin(A)+1, end(A), [&](pii x, pii y) { return ccw(A[0], x, y)<0; });
	if(N>300) {
		cout<<N<<'\n';
		reverse(begin(A)+1, end(A));
		for(auto[x,y]:A) cout<<x<<' '<<y<<'\n';
		return 0;
	}
	vector<vector<pii>> D1(N, vector<pii>(N)), D2=D1;
	int a=0, b=0, c=0;
	rep(i, 1, N) D2[0][i]={2, 0};
	rep(i, 0, N) rep(j, 0, i) {
		if(ccw(A[0], A[j], A[i])==0) continue;
		rep(k, 0, j) {
			long z=ccw(A[k], A[j], A[i]);
			#define maxi(a, b, c) if(a.x<b.x+1) a={b.x+1, c}
			if(z<0) maxi(D1[j][i], D2[k][j], k);
			if(z>0) maxi(D2[j][i], D1[k][j], k);
		}
		if(D2[a][b].x<D2[j][i].x) a=j, b=i;
	}
	if(D2[a][b].x<4) {
		cout<<"0\n";
		return 0;
	}
	cout<<D2[a][b].x<<'\n'<<A[0].x<<' '<<A[0].y<<'\n';
	do {
		cout<<A[b].x<<' '<<A[b].y<<'\n';
		b=c++%2 ? D1[a][b].y : D2[a][b].y;
		swap(a, b);
	} while(b);
}
# Verdict Execution time Memory Grader output
1 Correct 4 ms 376 KB Output is correct
2 Correct 7 ms 376 KB Output is correct
3 Correct 4 ms 376 KB Output is correct
4 Correct 4 ms 376 KB Output is correct
5 Correct 4 ms 376 KB Output is correct
6 Correct 4 ms 376 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 4 ms 376 KB Output is correct
9 Correct 10 ms 376 KB Output is correct
10 Correct 4 ms 376 KB Output is correct
11 Correct 4 ms 376 KB Output is correct
12 Correct 4 ms 376 KB Output is correct
13 Correct 4 ms 376 KB Output is correct
14 Correct 4 ms 376 KB Output is correct
15 Correct 4 ms 376 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 420 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 3 ms 380 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 2 ms 380 KB Output is correct
13 Correct 2 ms 376 KB Output is correct
14 Correct 2 ms 376 KB Output is correct
15 Correct 2 ms 376 KB Output is correct
16 Correct 2 ms 376 KB Output is correct
17 Correct 2 ms 376 KB Output is correct
18 Correct 2 ms 376 KB Output is correct
19 Correct 3 ms 376 KB Output is correct
20 Correct 2 ms 376 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 420 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 3 ms 380 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 2 ms 380 KB Output is correct
13 Correct 2 ms 376 KB Output is correct
14 Correct 2 ms 376 KB Output is correct
15 Correct 2 ms 376 KB Output is correct
16 Correct 2 ms 376 KB Output is correct
17 Correct 2 ms 376 KB Output is correct
18 Correct 2 ms 376 KB Output is correct
19 Correct 3 ms 376 KB Output is correct
20 Correct 2 ms 376 KB Output is correct
21 Correct 26 ms 1656 KB Output is correct
22 Correct 27 ms 1656 KB Output is correct
23 Correct 26 ms 1528 KB Output is correct
24 Correct 33 ms 1824 KB Output is correct
25 Correct 33 ms 1784 KB Output is correct
26 Correct 34 ms 1824 KB Output is correct
27 Correct 31 ms 1784 KB Output is correct
28 Correct 31 ms 1784 KB Output is correct
29 Correct 31 ms 1784 KB Output is correct
30 Correct 34 ms 1856 KB Output is correct
31 Correct 44 ms 1784 KB Output is correct
32 Correct 34 ms 1784 KB Output is correct
33 Correct 26 ms 1912 KB Output is correct
34 Correct 26 ms 1784 KB Output is correct
35 Correct 26 ms 1784 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 4 ms 376 KB Output is correct
2 Correct 7 ms 376 KB Output is correct
3 Correct 4 ms 376 KB Output is correct
4 Correct 4 ms 376 KB Output is correct
5 Correct 4 ms 376 KB Output is correct
6 Correct 4 ms 376 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 4 ms 376 KB Output is correct
9 Correct 10 ms 376 KB Output is correct
10 Correct 4 ms 376 KB Output is correct
11 Correct 4 ms 376 KB Output is correct
12 Correct 4 ms 376 KB Output is correct
13 Correct 4 ms 376 KB Output is correct
14 Correct 4 ms 376 KB Output is correct
15 Correct 4 ms 376 KB Output is correct
16 Correct 2 ms 376 KB Output is correct
17 Correct 2 ms 376 KB Output is correct
18 Correct 2 ms 376 KB Output is correct
19 Correct 2 ms 420 KB Output is correct
20 Correct 2 ms 376 KB Output is correct
21 Correct 2 ms 376 KB Output is correct
22 Correct 2 ms 376 KB Output is correct
23 Correct 3 ms 380 KB Output is correct
24 Correct 2 ms 376 KB Output is correct
25 Correct 2 ms 376 KB Output is correct
26 Correct 2 ms 376 KB Output is correct
27 Correct 2 ms 380 KB Output is correct
28 Correct 2 ms 376 KB Output is correct
29 Correct 2 ms 376 KB Output is correct
30 Correct 2 ms 376 KB Output is correct
31 Correct 2 ms 376 KB Output is correct
32 Correct 2 ms 376 KB Output is correct
33 Correct 2 ms 376 KB Output is correct
34 Correct 3 ms 376 KB Output is correct
35 Correct 2 ms 376 KB Output is correct
36 Correct 26 ms 1656 KB Output is correct
37 Correct 27 ms 1656 KB Output is correct
38 Correct 26 ms 1528 KB Output is correct
39 Correct 33 ms 1824 KB Output is correct
40 Correct 33 ms 1784 KB Output is correct
41 Correct 34 ms 1824 KB Output is correct
42 Correct 31 ms 1784 KB Output is correct
43 Correct 31 ms 1784 KB Output is correct
44 Correct 31 ms 1784 KB Output is correct
45 Correct 34 ms 1856 KB Output is correct
46 Correct 44 ms 1784 KB Output is correct
47 Correct 34 ms 1784 KB Output is correct
48 Correct 26 ms 1912 KB Output is correct
49 Correct 26 ms 1784 KB Output is correct
50 Correct 26 ms 1784 KB Output is correct
51 Correct 4 ms 504 KB Output is correct
52 Correct 4 ms 504 KB Output is correct
53 Correct 4 ms 504 KB Output is correct
54 Incorrect 4 ms 504 KB Output isn't correct
55 Halted 0 ms 0 KB -