Submission #27440

# Submission time Handle Problem Language Result Execution time Memory
27440 2017-07-12T15:24:22 Z gs14004 Relay (COI16_relay) C++14
100 / 100
116 ms 10844 KB
#include <bits/stdc++.h>
using namespace std;
typedef long long lint;
typedef long double llf;
typedef pair<int, int> pi;

struct pnt{
	int first, second, idx;
};

lint ccw(pi a, pi b, pi c){
	int dx1 = b.first - a.first;
	int dy1 = b.second - a.second;
	int dx2 = c.first - a.first;
	int dy2 = c.second - a.second;
	return 1ll * dx1 * dy2 - 1ll * dy1 * dx2;
}

lint ccw(pnt a, pnt b, pnt c){
	int dx1 = b.first - a.first;
	int dy1 = b.second - a.second;
	int dx2 = c.first - a.first;
	int dy2 = c.second - a.second;
	return 1ll * dx1 * dy2 - 1ll * dy1 * dx2;
}

lint dist(pnt a, pnt b){
	int dx = b.first - a.first;
	int dy = b.second - a.second;
	return 1ll * dx * dx + 1ll * dy * dy;
}

int n, m;
pi a[100005], b[100005];

void getch(vector<pnt> &v){
	swap(v[0], *min_element(v.begin(), v.end(), [&](const pnt &a, const pnt &b){
		return pi(a.first, a.second) < pi(b.first, b.second);
	}));
	sort(v.begin() + 1, v.end(), [&](const pnt &a, const pnt &b){
		lint k = ccw(v[0], a, b);
		if(k != 0) return k > 0;
		return dist(v[0], a) < dist(v[0], b);
	});
	vector<pnt> h;
	for(auto &i : v){
		while(h.size() >= 2 && ccw(h[h.size() - 2], h.back(), i) <= 0){
			h.pop_back();
		}
		h.push_back(i);
	}
	v = h;
}


int main(){
	scanf("%d",&n);
	for(int i=0; i<n; i++) scanf("%d %d",&a[i].first,&a[i].second);
	scanf("%d",&m);
	for(int i=0; i<m; i++) scanf("%d %d",&b[i].first,&b[i].second);
	int lp = 0, rp = 0;
	for(int i=1; i<m; i++){
		if(ccw(a[0], b[lp], b[i]) < 0) lp = i;
		if(ccw(a[0], b[rp], b[i]) > 0) rp = i;
	}
	vector<pnt> lv, rv;
	vector<pi> mv;
	for(int i=1; i<n; i++){
		if(ccw(a[0], b[lp], a[i]) <= 0){
			lv.push_back({a[i].first, a[i].second, -1});
		}
		if(ccw(a[0], b[rp], a[i]) >= 0){
			rv.push_back({a[i].first, a[i].second, -1});
		}
		if(ccw(a[0], b[lp], a[i]) > 0 && ccw(a[0], b[rp], a[i]) < 0 && ccw(b[lp], b[rp], a[i]) <= 0){
			mv.push_back(a[i]);
		}
	}
	for(int i=0; i<m; i++){
		lv.push_back({b[i].first, b[i].second, i});
		rv.push_back({b[i].first, b[i].second, i});
	}
	getch(lv);
	getch(rv);
	int ps = -1, pe = -1;
	pi ls, rs;
	for(int i=0; i<lv.size(); i++){
		if(lv[i].idx == -1 && lv[(i+1)%lv.size()].idx != -1){
			ls = pi(lv[i].first, lv[i].second);
			ps = lv[(i+1)%lv.size()].idx;
		}
	}
	for(int i=0; i<rv.size(); i++){
		if(rv[(i+1)%rv.size()].idx == -1 && rv[i].idx != -1){
			rs = pi(rv[(i+1)%rv.size()].first, rv[(i+1)%rv.size()].second);
			pe = rv[i].idx;
		}
	}
	int ans = 0;
	for(auto &i : mv){
		bool okps = (ps == -1);
		bool okpe = (pe == -1);
		if(!okpe && ccw(a[0], b[pe], i) < 0 && ccw(rs, b[pe], i) < 0) okpe = 1;
		if(!okps && ccw(a[0], b[ps], i) > 0 && ccw(ls, b[ps], i) > 0) okps = 1;
		if(okps && okpe) ans++;
	}
	cout << n - ans - 1;
}

Compilation message

relay.cpp: In function 'int main()':
relay.cpp:87:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<lv.size(); i++){
                ^
relay.cpp:93:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<rv.size(); i++){
                ^
relay.cpp:57:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
relay.cpp:58:64: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=0; i<n; i++) scanf("%d %d",&a[i].first,&a[i].second);
                                                                ^
relay.cpp:59:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&m);
                ^
relay.cpp:60:64: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=0; i<m; i++) scanf("%d %d",&b[i].first,&b[i].second);
                                                                ^
# Verdict Execution time Memory Grader output
1 Correct 0 ms 3584 KB Output is correct
2 Correct 0 ms 3584 KB Output is correct
3 Correct 0 ms 3584 KB Output is correct
4 Correct 0 ms 3584 KB Output is correct
5 Correct 0 ms 3584 KB Output is correct
6 Correct 0 ms 3584 KB Output is correct
7 Correct 0 ms 3584 KB Output is correct
8 Correct 0 ms 3584 KB Output is correct
9 Correct 0 ms 3584 KB Output is correct
10 Correct 0 ms 3584 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 3584 KB Output is correct
2 Correct 0 ms 3584 KB Output is correct
3 Correct 0 ms 3584 KB Output is correct
4 Correct 0 ms 3584 KB Output is correct
5 Correct 0 ms 3584 KB Output is correct
6 Correct 0 ms 3584 KB Output is correct
7 Correct 0 ms 3584 KB Output is correct
8 Correct 0 ms 3584 KB Output is correct
9 Correct 0 ms 3584 KB Output is correct
10 Correct 0 ms 3584 KB Output is correct
11 Correct 3 ms 3900 KB Output is correct
12 Correct 3 ms 3896 KB Output is correct
13 Correct 0 ms 3732 KB Output is correct
14 Correct 0 ms 3736 KB Output is correct
15 Correct 0 ms 3724 KB Output is correct
16 Correct 0 ms 3724 KB Output is correct
17 Correct 0 ms 3732 KB Output is correct
18 Correct 3 ms 3724 KB Output is correct
19 Correct 0 ms 3724 KB Output is correct
20 Correct 0 ms 3724 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 3584 KB Output is correct
2 Correct 0 ms 3584 KB Output is correct
3 Correct 0 ms 3584 KB Output is correct
4 Correct 0 ms 3584 KB Output is correct
5 Correct 0 ms 3584 KB Output is correct
6 Correct 0 ms 3584 KB Output is correct
7 Correct 0 ms 3584 KB Output is correct
8 Correct 0 ms 3584 KB Output is correct
9 Correct 0 ms 3584 KB Output is correct
10 Correct 0 ms 3584 KB Output is correct
11 Correct 36 ms 5460 KB Output is correct
12 Correct 29 ms 5460 KB Output is correct
13 Correct 36 ms 5460 KB Output is correct
14 Correct 33 ms 5460 KB Output is correct
15 Correct 39 ms 5588 KB Output is correct
16 Correct 39 ms 5396 KB Output is correct
17 Correct 59 ms 5832 KB Output is correct
18 Correct 39 ms 5980 KB Output is correct
19 Correct 29 ms 5364 KB Output is correct
20 Correct 46 ms 5364 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 3584 KB Output is correct
2 Correct 0 ms 3584 KB Output is correct
3 Correct 0 ms 3584 KB Output is correct
4 Correct 0 ms 3584 KB Output is correct
5 Correct 0 ms 3584 KB Output is correct
6 Correct 0 ms 3584 KB Output is correct
7 Correct 0 ms 3584 KB Output is correct
8 Correct 0 ms 3584 KB Output is correct
9 Correct 0 ms 3584 KB Output is correct
10 Correct 0 ms 3584 KB Output is correct
11 Correct 3 ms 3900 KB Output is correct
12 Correct 3 ms 3896 KB Output is correct
13 Correct 0 ms 3732 KB Output is correct
14 Correct 0 ms 3736 KB Output is correct
15 Correct 0 ms 3724 KB Output is correct
16 Correct 0 ms 3724 KB Output is correct
17 Correct 0 ms 3732 KB Output is correct
18 Correct 3 ms 3724 KB Output is correct
19 Correct 0 ms 3724 KB Output is correct
20 Correct 0 ms 3724 KB Output is correct
21 Correct 36 ms 5460 KB Output is correct
22 Correct 29 ms 5460 KB Output is correct
23 Correct 36 ms 5460 KB Output is correct
24 Correct 33 ms 5460 KB Output is correct
25 Correct 39 ms 5588 KB Output is correct
26 Correct 39 ms 5396 KB Output is correct
27 Correct 59 ms 5832 KB Output is correct
28 Correct 39 ms 5980 KB Output is correct
29 Correct 29 ms 5364 KB Output is correct
30 Correct 46 ms 5364 KB Output is correct
31 Correct 113 ms 10844 KB Output is correct
32 Correct 116 ms 10844 KB Output is correct
33 Correct 63 ms 9564 KB Output is correct
34 Correct 59 ms 9564 KB Output is correct
35 Correct 79 ms 8532 KB Output is correct
36 Correct 66 ms 6996 KB Output is correct
37 Correct 96 ms 8316 KB Output is correct
38 Correct 99 ms 8028 KB Output is correct
39 Correct 69 ms 6804 KB Output is correct
40 Correct 76 ms 6996 KB Output is correct