답안 #63153 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
63153	2018-08-01T01:19:19 Z	khsoo01	공룡 발자국 (KOI18_footprint)	C++11	100 / 100	1911 ms	84672 KB

footprint

#include<bits/stdc++.h>
#define X first
#define Y second
using namespace std;
typedef pair<int,int> pii;

const int N = 3005, inf = 1e9;

int n;
pii a[N], dt[N][N][2], piv;

vector<int> ans;

long long ccw (pii &A, pii &B, pii &C) {
	return (1ll*A.X*B.Y+1ll*B.X*C.Y+1ll*C.X*A.Y) - (1ll*A.Y*B.X+1ll*B.Y*C.X+1ll*C.Y*A.X);
}

bool cmp (pii &A, pii &B) {
	return ccw(piv, A, B) > 0;
}

bool cmp2 (int A, int B) {
	return ccw(piv, a[A], a[B]) > 0;
}

int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++) {
		scanf("%d%d",&a[i].X,&a[i].Y);
		if(a[i].Y < a[1].Y) swap(a[i], a[1]);
	}
	piv = a[1];
	sort(a+2, a+1+n, cmp);
	for(int i=1;i<=n;i++) {
		dt[1][i][0] = {1, 0};
	}
	for(int k=2;k<=n;k++) {
		vector<int> A, B;
		A.push_back(1);
		for(int i=2;i<k;i++) {
			if(ccw(a[1], a[k], a[i]) != 0) A.push_back(i);
		}
		for(int i=k+1;i<=n;i++) {
			if(ccw(a[1], a[k], a[i]) != 0) B.push_back(i);
		}
		piv = a[k];
		sort(A.begin(), A.end(), cmp2);
		sort(B.begin(), B.end(), cmp2);
		int j = 0;
		pii V = {-inf, -inf};
		for(int i=0;i<=(int)A.size();i++) {
			int T = (i < (int)A.size() ? A[i] : k);
			while(j<(int)B.size() && ccw(a[T], a[k], a[B[j]]) <= 0) {
				dt[k][B[j]][1] = max(dt[k][B[j]][1], V);
				j++;
			}
			V = max(V, {dt[T][k][0].X+1, T});
		}
		j = (int)B.size()-1;
		V = {-inf, -inf};
		for(int i=(int)A.size()-1;i>=-1;i--) {
			int T = (i >= 0 ? A[i] : k);
			while(j >= 0 && ccw(a[T], a[k], a[B[j]]) >= 0) {
				dt[k][B[j]][0] = max(dt[k][B[j]][0], V);
				j--;
			}
			V = max(V, {dt[T][k][1].X+1, T});
		}
	}
	int V = 0, A, B, C = 0;
	for(int i=1;i<=n;i++) {
		for(int j=1;j<=n;j++) {
			if(V < dt[i][j][0].X) {
				V = dt[i][j][0].X;
				A = i;
				B = j;
			}
		}
	}
	if(V == 1) {
		puts("0");
		return 0;
	}
	for(int i=0;i<V;i++) {
		ans.push_back(B);
		int T = A;
		A = dt[A][B][C].Y;
		B = T;
		C ^= 1;
	}
	ans.push_back(1);
	reverse(ans.begin(), ans.end());
	printf("%d\n",(int)ans.size());
	for(auto &T : ans) {
		printf("%d %d\n", a[T].X, a[T].Y);
	}
}

Compilation message

footprint.cpp: In function 'int main()':
footprint.cpp:28:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
footprint.cpp:30:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&a[i].X,&a[i].Y);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
footprint.cpp:88:5: warning: 'A' may be used uninitialized in this function [-Wmaybe-uninitialized]
   A = dt[A][B][C].Y;
     ^

Subtask #1
14.0 / 14.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1393 ms	70052 KB	Output is correct
2	Correct	1426 ms	72624 KB	Output is correct
3	Correct	1449 ms	72624 KB	Output is correct
4	Correct	1346 ms	72888 KB	Output is correct
5	Correct	1393 ms	72888 KB	Output is correct
6	Correct	1487 ms	73168 KB	Output is correct
7	Correct	1402 ms	73168 KB	Output is correct
8	Correct	1406 ms	73484 KB	Output is correct
9	Correct	1496 ms	73716 KB	Output is correct
10	Correct	1544 ms	73716 KB	Output is correct
11	Correct	1442 ms	73716 KB	Output is correct
12	Correct	1603 ms	74140 KB	Output is correct
13	Correct	1504 ms	75540 KB	Output is correct
14	Correct	1550 ms	75540 KB	Output is correct
15	Correct	1444 ms	75540 KB	Output is correct

Subtask #2
12.0 / 12.0

#	결과	실행 시간	메모리	Grader output
1	Correct	2 ms	75540 KB	Output is correct
2	Correct	2 ms	75540 KB	Output is correct
3	Correct	2 ms	75540 KB	Output is correct
4	Correct	3 ms	75540 KB	Output is correct
5	Correct	2 ms	75540 KB	Output is correct
6	Correct	3 ms	75540 KB	Output is correct
7	Correct	3 ms	75540 KB	Output is correct
8	Correct	3 ms	75540 KB	Output is correct
9	Correct	2 ms	75540 KB	Output is correct
10	Correct	2 ms	75540 KB	Output is correct
11	Correct	4 ms	75540 KB	Output is correct
12	Correct	3 ms	75540 KB	Output is correct
13	Correct	3 ms	75540 KB	Output is correct
14	Correct	2 ms	75540 KB	Output is correct
15	Correct	3 ms	75540 KB	Output is correct
16	Correct	3 ms	75540 KB	Output is correct
17	Correct	2 ms	75540 KB	Output is correct
18	Correct	3 ms	75540 KB	Output is correct
19	Correct	2 ms	75540 KB	Output is correct
20	Correct	3 ms	75540 KB	Output is correct

Subtask #3
29.0 / 29.0

#	결과	실행 시간	메모리	Grader output
1	Correct	2 ms	75540 KB	Output is correct
2	Correct	2 ms	75540 KB	Output is correct
3	Correct	2 ms	75540 KB	Output is correct
4	Correct	3 ms	75540 KB	Output is correct
5	Correct	2 ms	75540 KB	Output is correct
6	Correct	3 ms	75540 KB	Output is correct
7	Correct	3 ms	75540 KB	Output is correct
8	Correct	3 ms	75540 KB	Output is correct
9	Correct	2 ms	75540 KB	Output is correct
10	Correct	2 ms	75540 KB	Output is correct
11	Correct	4 ms	75540 KB	Output is correct
12	Correct	3 ms	75540 KB	Output is correct
13	Correct	3 ms	75540 KB	Output is correct
14	Correct	2 ms	75540 KB	Output is correct
15	Correct	3 ms	75540 KB	Output is correct
16	Correct	3 ms	75540 KB	Output is correct
17	Correct	2 ms	75540 KB	Output is correct
18	Correct	3 ms	75540 KB	Output is correct
19	Correct	2 ms	75540 KB	Output is correct
20	Correct	3 ms	75540 KB	Output is correct
21	Correct	20 ms	75540 KB	Output is correct
22	Correct	15 ms	75540 KB	Output is correct
23	Correct	15 ms	75540 KB	Output is correct
24	Correct	23 ms	75540 KB	Output is correct
25	Correct	18 ms	75540 KB	Output is correct
26	Correct	17 ms	75540 KB	Output is correct
27	Correct	17 ms	75540 KB	Output is correct
28	Correct	17 ms	75540 KB	Output is correct
29	Correct	16 ms	75540 KB	Output is correct
30	Correct	18 ms	75540 KB	Output is correct
31	Correct	21 ms	75540 KB	Output is correct
32	Correct	21 ms	75540 KB	Output is correct
33	Correct	12 ms	75540 KB	Output is correct
34	Correct	13 ms	75540 KB	Output is correct
35	Correct	15 ms	75540 KB	Output is correct

Subtask #4
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1393 ms	70052 KB	Output is correct
2	Correct	1426 ms	72624 KB	Output is correct
3	Correct	1449 ms	72624 KB	Output is correct
4	Correct	1346 ms	72888 KB	Output is correct
5	Correct	1393 ms	72888 KB	Output is correct
6	Correct	1487 ms	73168 KB	Output is correct
7	Correct	1402 ms	73168 KB	Output is correct
8	Correct	1406 ms	73484 KB	Output is correct
9	Correct	1496 ms	73716 KB	Output is correct
10	Correct	1544 ms	73716 KB	Output is correct
11	Correct	1442 ms	73716 KB	Output is correct
12	Correct	1603 ms	74140 KB	Output is correct
13	Correct	1504 ms	75540 KB	Output is correct
14	Correct	1550 ms	75540 KB	Output is correct
15	Correct	1444 ms	75540 KB	Output is correct
16	Correct	2 ms	75540 KB	Output is correct
17	Correct	2 ms	75540 KB	Output is correct
18	Correct	2 ms	75540 KB	Output is correct
19	Correct	3 ms	75540 KB	Output is correct
20	Correct	2 ms	75540 KB	Output is correct
21	Correct	3 ms	75540 KB	Output is correct
22	Correct	3 ms	75540 KB	Output is correct
23	Correct	3 ms	75540 KB	Output is correct
24	Correct	2 ms	75540 KB	Output is correct
25	Correct	2 ms	75540 KB	Output is correct
26	Correct	4 ms	75540 KB	Output is correct
27	Correct	3 ms	75540 KB	Output is correct
28	Correct	3 ms	75540 KB	Output is correct
29	Correct	2 ms	75540 KB	Output is correct
30	Correct	3 ms	75540 KB	Output is correct
31	Correct	3 ms	75540 KB	Output is correct
32	Correct	2 ms	75540 KB	Output is correct
33	Correct	3 ms	75540 KB	Output is correct
34	Correct	2 ms	75540 KB	Output is correct
35	Correct	3 ms	75540 KB	Output is correct
36	Correct	20 ms	75540 KB	Output is correct
37	Correct	15 ms	75540 KB	Output is correct
38	Correct	15 ms	75540 KB	Output is correct
39	Correct	23 ms	75540 KB	Output is correct
40	Correct	18 ms	75540 KB	Output is correct
41	Correct	17 ms	75540 KB	Output is correct
42	Correct	17 ms	75540 KB	Output is correct
43	Correct	17 ms	75540 KB	Output is correct
44	Correct	16 ms	75540 KB	Output is correct
45	Correct	18 ms	75540 KB	Output is correct
46	Correct	21 ms	75540 KB	Output is correct
47	Correct	21 ms	75540 KB	Output is correct
48	Correct	12 ms	75540 KB	Output is correct
49	Correct	13 ms	75540 KB	Output is correct
50	Correct	15 ms	75540 KB	Output is correct
51	Correct	1470 ms	75540 KB	Output is correct
52	Correct	1521 ms	75540 KB	Output is correct
53	Correct	1584 ms	75956 KB	Output is correct
54	Correct	1697 ms	84252 KB	Output is correct
55	Correct	1761 ms	84252 KB	Output is correct
56	Correct	1911 ms	84340 KB	Output is correct
57	Correct	1851 ms	84340 KB	Output is correct
58	Correct	1775 ms	84340 KB	Output is correct
59	Correct	1820 ms	84356 KB	Output is correct
60	Correct	1875 ms	84592 KB	Output is correct
61	Correct	1778 ms	84592 KB	Output is correct
62	Correct	1812 ms	84652 KB	Output is correct
63	Correct	1057 ms	84652 KB	Output is correct
64	Correct	1189 ms	84652 KB	Output is correct
65	Correct	1093 ms	84652 KB	Output is correct
66	Correct	1448 ms	84652 KB	Output is correct
67	Correct	1417 ms	84652 KB	Output is correct
68	Correct	1441 ms	84672 KB	Output is correct

답안 #63153

Compilation message

Subtask #1 14.0 / 14.0

Subtask #2 12.0 / 12.0

Subtask #3 29.0 / 29.0

Subtask #4 45.0 / 45.0

Subtask #1
14.0 / 14.0

Subtask #2
12.0 / 12.0

Subtask #3
29.0 / 29.0

Subtask #4
45.0 / 45.0