oj.uz

Submission #230853

# Submission time Handle Problem Language Result Execution time Memory
230853 2020-05-11T22:38:05 Z frodakcin Relay (COI16_relay) C++11
57 / 100
 142 ms 13996 KB 
#include <cstdio>
#include <cassert>

using ll = long long;
struct vec
{
public:
	ll x, y;
	vec(ll x=0, ll y=0) : x(x), y(y) {}
	void in(){scanf("%lld%lld", &x, &y);}
	ll operator / (vec o) const {return x*o.y-o.x*y;}
	ll operator * (vec o) const {return x*o.x+y*o.y;}

	vec& operator += (vec o) {return x+=o.x, y+=o.y, *this;}
	vec& operator -= (vec o) {return x-=o.x, y-=o.y, *this;}

	friend vec operator + (vec a, vec b) {return a += b;}
	friend vec operator - (vec a, vec b) {return a -= b;}
};

const int MN = 2e5 + 10;
int N, M, low[MN], high[MN], ans;
bool mayday[MN];
vec a[MN], b[MN];
struct ray
{
public: 
	vec s, d;
};
ray bot, top;
int main(void)
{
	scanf("%d", &N);
	for(int i=0;i<N;++i)
		a[i].in();
	scanf("%d", &M);
	for(int i=0;i<M;++i)
		b[i].in(), b[i+M]=b[i];//for convenience
	for(int i=0,l,r,m,u,v,z;i<N;++i)
	{
		vec x=a[i];
		//printf("INFO FOR (id: %d), (%lld, %lld) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n", i+1, x.x, x.y);
		z=0;
		vec d=b[z]-x;
		if(d/(b[1]-b[0]) == 0)
			d=b[++z]-x;
		if(d/(b[z+1]-b[z]) > 0)
		{
			l=z,r=M+z;
			for(;r-l>1;)
			{
				m=l+(r-l)/2;
				if(d/(b[m]-b[z]) < 0)
					r=m;
				else
					l=m;
			}
			u=l;
		}
		else
			u=z;
		u%=M;
		assert((b[u]-x)/(b[u+1]-x) <= 0);

		//b[u] is on the same side as a[i]
		d=b[u]-x;
		l=u,r=u+M;
		for(;r-l>1;)
		{
			m=l+(r-l)/2;
			if(d/(b[m]-b[u]) < 0)
				l=m;
			else
				r=m;
		}
		v=l%M;

		//printf("VALS: %d %d\n", u, v);
		assert((b[v]-x)/(b[v+1]-x) >= 0);

		//u<->v cut the convex hull
		//u is on closer side
		//lower hull: v...u
		{
			l=v,r=u;
			if(r<l)r+=M;
			--l;
			for(;r-l>1;)
			{
				m=l+(r-l)/2;
				if((b[m]-x)/(b[m+1]-b[m])>0)
					l=m;
				else
					r=m;
			}
			low[i] = r%M;
		}
		//upper hull: u...v
		{
			l=u,r=v;
			if(r<l) r+=M;
			--l;
			for(;r-l>1;)
			{
				m=l+(r-l)/2;
				if((b[m]-x)/(b[m+1]-b[m])<=0)
					l=m;
				else
					r=m;
			}
			high[i] = r%M;
		}

		//printf("\tLOW: (%lld, %lld)\n", b[low[i]].x, b[low[i]].y);
		//printf("\tHIGH: (%lld, %lld)\n", b[high[i]].x, b[high[i]].y);
		//printf("\n");

		assert((b[low[i]]-x)/(b[low[i]+1]-b[low[i]]) <= 0);
		assert((b[low[i]+M-1]-x)/(b[low[i]]-b[low[i]+M-1]) > 0);

		assert((b[high[i]]-x)/(b[high[i]+1]-b[high[i]]) > 0);
		assert((b[high[i]+M-1]-x)/(b[high[i]]-b[high[i]+M-1]) <= 0);
	}
	bot = {b[low[0]], b[low[0]]-a[0]};
	top = {b[high[0]], b[high[0]]-a[0]};
	vec bot0 = b[low[0]]-a[0];
	vec top0 = b[high[0]]-a[0];
	for(int i=1;i<N;++i)
	{
		if(bot.d/(a[i]-bot.s)>=0 || top.d/(a[i]-top.s)<=0)
			mayday[i] = 1;
		else if((a[i]-top.s)/(a[i]-bot.s) >= 0)
			mayday[i] = 1;
	}
	for(int i=1;i<N;++i)
		if(mayday[i])
		{
			//printf("MAYDAY: (id: %d), (%lld, %lld)\n", i+1, a[i].x, a[i].y);
			ray bot2 = {b[low[i]], b[low[i]]-a[i]};
			ray top2 = {b[high[i]], b[high[i]]-a[i]};

			if(bot0/bot2.d <= 0 && bot.d/bot2.d < 0)
				bot = bot2;
			if(top0/top2.d >= 0 && top.d/top2.d > 0)
				top = top2;
		}
	if((top.s-a[0])/(bot.s-a[0]) <= 0)
		return printf("%d\n", N-1), 0;
	for(int i=1;i<N;++i)
	{
		bool relay=0;
		if(bot.d/(a[i]-bot.s)>=0 || top.d/(a[i]-top.s)<=0)
			relay = 1;
		else if((a[i]-top.s)/(a[i]-bot.s) >= 0)
			relay = 1;
		if(relay)
		{
			++ans;
			//printf("RELAY: (id: %d), (%lld, %lld)\n", i+1, a[i].x, a[i].y);
		}
	}
	printf("%d\n", ans);
	return 0;
}

Compilation message

relay.cpp: In function 'int main()':
relay.cpp:33:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
relay.cpp:36:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &M);
  ~~~~~^~~~~~~~~~
relay.cpp: In member function 'void vec::in()':
relay.cpp:10:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  void in(){scanf("%lld%lld", &x, &y);}
            ~~~~~^~~~~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 6528 KB Output is correct
2 Correct 8 ms 6656 KB Output is correct
3 Correct 8 ms 6656 KB Output is correct
4 Correct 8 ms 6656 KB Output is correct
5 Correct 8 ms 6656 KB Output is correct
6 Correct 8 ms 6656 KB Output is correct
7 Correct 8 ms 6656 KB Output is correct
8 Correct 8 ms 6528 KB Output is correct
9 Correct 8 ms 6656 KB Output is correct
10 Correct 7 ms 6528 KB Output is correct

Subtask #2
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 6528 KB Output is correct
2 Correct 8 ms 6656 KB Output is correct
3 Correct 8 ms 6656 KB Output is correct
4 Correct 8 ms 6656 KB Output is correct
5 Correct 8 ms 6656 KB Output is correct
6 Correct 8 ms 6656 KB Output is correct
7 Correct 8 ms 6656 KB Output is correct
8 Correct 8 ms 6528 KB Output is correct
9 Correct 8 ms 6656 KB Output is correct
10 Correct 7 ms 6528 KB Output is correct
11 Correct 11 ms 6656 KB Output is correct
12 Correct 10 ms 6656 KB Output is correct
13 Correct 10 ms 6656 KB Output is correct
14 Correct 10 ms 6656 KB Output is correct
15 Correct 10 ms 6656 KB Output is correct
16 Correct 10 ms 6656 KB Output is correct
17 Correct 10 ms 6656 KB Output is correct
18 Correct 11 ms 6656 KB Output is correct
19 Correct 10 ms 6656 KB Output is correct
20 Correct 10 ms 6656 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 6528 KB Output is correct
2 Correct 8 ms 6656 KB Output is correct
3 Correct 8 ms 6656 KB Output is correct
4 Correct 8 ms 6656 KB Output is correct
5 Correct 8 ms 6656 KB Output is correct
6 Correct 8 ms 6656 KB Output is correct
7 Correct 8 ms 6656 KB Output is correct
8 Correct 8 ms 6528 KB Output is correct
9 Correct 8 ms 6656 KB Output is correct
10 Correct 7 ms 6528 KB Output is correct
11 Correct 56 ms 7416 KB Output is correct
12 Correct 55 ms 7416 KB Output is correct
13 Correct 51 ms 7416 KB Output is correct
14 Correct 53 ms 7416 KB Output is correct
15 Correct 70 ms 7416 KB Output is correct
16 Correct 64 ms 7416 KB Output is correct
17 Correct 67 ms 7416 KB Output is correct
18 Correct 67 ms 7416 KB Output is correct
19 Correct 64 ms 7416 KB Output is correct
20 Correct 64 ms 7416 KB Output is correct

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 6528 KB Output is correct
2 Correct 8 ms 6656 KB Output is correct
3 Correct 8 ms 6656 KB Output is correct
4 Correct 8 ms 6656 KB Output is correct
5 Correct 8 ms 6656 KB Output is correct
6 Correct 8 ms 6656 KB Output is correct
7 Correct 8 ms 6656 KB Output is correct
8 Correct 8 ms 6528 KB Output is correct
9 Correct 8 ms 6656 KB Output is correct
10 Correct 7 ms 6528 KB Output is correct
11 Correct 11 ms 6656 KB Output is correct
12 Correct 10 ms 6656 KB Output is correct
13 Correct 10 ms 6656 KB Output is correct
14 Correct 10 ms 6656 KB Output is correct
15 Correct 10 ms 6656 KB Output is correct
16 Correct 10 ms 6656 KB Output is correct
17 Correct 10 ms 6656 KB Output is correct
18 Correct 11 ms 6656 KB Output is correct
19 Correct 10 ms 6656 KB Output is correct
20 Correct 10 ms 6656 KB Output is correct
21 Correct 56 ms 7416 KB Output is correct
22 Correct 55 ms 7416 KB Output is correct
23 Correct 51 ms 7416 KB Output is correct
24 Correct 53 ms 7416 KB Output is correct
25 Correct 70 ms 7416 KB Output is correct
26 Correct 64 ms 7416 KB Output is correct
27 Correct 67 ms 7416 KB Output is correct
28 Correct 67 ms 7416 KB Output is correct
29 Correct 64 ms 7416 KB Output is correct
30 Correct 64 ms 7416 KB Output is correct
31 Correct 113 ms 7376 KB Output is correct
32 Correct 111 ms 7416 KB Output is correct
33 Correct 84 ms 7416 KB Output is correct
34 Correct 85 ms 7416 KB Output is correct
35 Correct 139 ms 7588 KB Output is correct
36 Correct 142 ms 7416 KB Output is correct
37 Correct 131 ms 7420 KB Output is correct
38 Correct 131 ms 7416 KB Output is correct
39 Runtime error 93 ms 13996 KB Execution killed with signal 11 (could be triggered by violating memory limits)
40 Halted 0 ms 0 KB -