Submission #83570

#	Time	Username	Problem	Language	Result	Execution time	Memory
83570		faceless	The Forest of Fangorn (CEOI14_fangorn)	C++17	80 / 100	3037 ms	17148 KiB

fangorn

#include <bits/stdc++.h>
#define MP make_pair
#define F first
#define PB push_back
#define S second
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
const int mod = (int)1e9 + 7;
const int maxn = 1e4 + 4;
const ll inf = 1e18;
const pair <int, int> Oxy = {0, 0};

pii operator + (pii fi, pii se) {
	return {fi.F + se.F, fi.S + se.S};
}

pii operator - (pii fi, pii se) {
	return {fi.F - se.F, fi.S - se.S};
}

ll operator * (pii fi, pii se) {
	return 1ll * fi.F * se.S - 1ll * fi.S * se.F;
}

int n;
pii p[maxn], c[maxn];
vector <int> v[maxn];

inline bool isright (pii A, pii B, pii C) {
	pii AB = B - A;
	pii AC = C - A;
	return (AB * AC) < 0;
}

int district (pii pnt, int x) {
	int lo = 0, hi = n - 1;
	pii A = p[x];
	pii B = p[v[x][0]];
	while (hi - lo > 1) {
		int mid = (hi + lo) >> 1;
		pii C = p[v[x][mid]];
		if (isright (B, A, B + A - C)) {
			if (isright (B, A, pnt) and !isright (C, A, pnt))
				hi = mid;
			else
				lo = mid;
		}
		else {
			if (isright (B, A, pnt) or !isright (C, A, pnt))
				hi = mid;
			else
				lo = mid;
		}
	}
	return hi;
}

inline int nahiye (pii vec) {
	if (vec.F >= 0 and vec.S <= 0)
		return 4;
	if (vec.F >= 0 and vec.S >= 0)
		return 1;
	if (vec.F <= 0 and vec.S <= 0)
		return 3;
	return 2;
}
bool cmp (int fi, int se) {
	int x = nahiye (p[fi]), y = nahiye (p[se]);
	if (x != y)
		return x > y;
	return isright (Oxy, p[fi], p[se]);
}

int d[maxn];

int main (){
	int w, h;
	scanf ("%d%d", &w, &h);
	pii s;
	scanf ("%d%d", &s.F, &s.S);
	int number_of_camps;
	scanf ("%d", &number_of_camps);
	for (int i = 0; i < number_of_camps; i++)
		scanf ("%d%d", &c[i].F, &c[i].S);
	scanf ("%d", &n);
	for (int i = 0; i < n; i++)
		scanf ("%d%d", &p[i].F, &p[i].S);
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (i == j)
				continue;
			v[i].PB (j);
			p[j] = p[i] - p[j];
		}
		sort (v[i].begin(), v[i].end(), cmp);
		for (int j = 0; j < n; j++) {
			if (i == j)
				continue;
			p[j] = p[j] - p[i];
			p[j] = Oxy - p[j];
		}
	}
	
	for (int i = 0; i < n; i++)
		d[i] = district (s, i);
	vector <int> ans;
	for (int i = 0; i < number_of_camps; i++) {
		bool found = 0;
		for (int j = 0; j < n; j++) {
			if (district (c[i], j) != d[j]) {
				found = 1;
				break;
			}
		}
		if (!found)
			ans.PB (i + 1);
	}
	int k = ans.size();
	printf ("%d\n", k);
	for (auto it : ans)
		printf ("%d ", it);
}

Compilation message (stderr)

fangorn.cpp: In function 'int main()':
fangorn.cpp:80:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d%d", &w, &h);
  ~~~~~~^~~~~~~~~~~~~~~~
fangorn.cpp:82:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d%d", &s.F, &s.S);
  ~~~~~~^~~~~~~~~~~~~~~~~~~~
fangorn.cpp:84:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d", &number_of_camps);
  ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
fangorn.cpp:86:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf ("%d%d", &c[i].F, &c[i].S);
   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
fangorn.cpp:87:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d", &n);
  ~~~~~~^~~~~~~~~~
fangorn.cpp:89:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf ("%d%d", &p[i].F, &p[i].S);
   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 0 / 20