#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include <ext/pb_ds/tree_policy.hpp>
//#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
//using namespace __gnu_pbds;
#define FOR(i,start,end) for(int i=start;i<(int)(end);i++)
#define FORE(i,start,end) for(int i=start;i<=(int)end;i++)
#define RFOR(i,start,end) for(int i = start; i>end; i--)
#define RFORE(i,start,end) for(int i = start; i>=end; i--)
#define all(a) a.begin(), a.end()
#define mt make_tuple
#define mp make_pair
#define v vector
#define sf scanf
#define pf printf
#define dvar(x) cout << #x << " := " << x << "\n"
#define darr(x,n) FOR(i,0,n) cout << #x << "[" << i << "]" << " := " << x[i] << "\n"
typedef long long ll;
typedef long double ld;
typedef pair<int, int > pii;
typedef pair<ll, ll> pll;
//template <class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T> void minn(T &a, T b) { a = min(a, b); }
template<class T> void maxx(T &a, T b) { a = max(a, b); }
void io() {
#ifdef LOCAL_PROJECT
freopen("input.in", "r", stdin); freopen("output.out", "w", stdout);
#else
/* online submission */
#endif
ios_base::sync_with_stdio(false); cin.tie(NULL);
}
const ll MOD = 1000000007LL;
const ll PRIME = 105943LL;
const ll INF = 1e18;
/****************************************************************/
const int SZ = 1e6;
struct DynamicArea {
ll sum = 0;
ll data[SZ][3];
int f = 0, b = -1;
void init(pll p) {
b++;
assert(b < SZ);
data[b][0] = p.first;
data[b][1] = p.second;
data[b][2] = 0;
}
ll calc(pll a, pll b) {
return a.second*b.first - a.first*b.second;
}
void push_back(pll p) {
b++;
assert(b < SZ);
data[b][0] = p.first;
data[b][1] = p.second;
data[b][2] = calc({ data[b - 1][0], data[b - 1][1] }, p);
sum += data[b][2];
}
void pop_front() {
f++;
assert(f <= b);
sum -= data[f][2];
}
ll query() {
return abs(sum + calc({ data[b][0], data[b][1] }, { data[f][0], data[f][1] }));
}
};
ll cross(const pll &O, const pll &A, const pll &B) {
return ((ll)(A.first - O.first)) * (B.second - O.second) - ((ll)(A.second - O.second)) * (B.first - O.first);
}
v<pll> convex_hull(v<pll> &P) {
sort(P.begin(), P.end()); P.erase(unique(P.begin(), P.end()), P.end());
int n = P.size();
if (n == 1) return P;
v<pll> bot = { P[0] };
FOR(i, 1, n) {
while (bot.size() > 1 && cross(bot[bot.size() - 2], bot.back(), P[i]) <= 0) bot.pop_back();
bot.push_back(P[i]);
}
bot.pop_back();
v<pll> up = { P[n - 1] };
RFORE(i, n - 1, 0) {
while (up.size() > 1 && cross(up[up.size() - 2], up.back(), P[i]) <= 0) up.pop_back();
up.push_back(P[i]);
}
up.pop_back();
bot.insert(bot.end(), up.begin(), up.end());
return bot;
}
#define X first
#define Y second
typedef pair<ll, ll> Point;
typedef pair<ll, ll> Vector;
Vector make_Vector(Point a, Point b) {
return make_pair(a.X - b.X, a.Y - b.Y); // a <--- b
}
ll dot(Vector u, Vector v) {
return ((u).X * (v).X + (u).Y * (v).Y);
}
bool up(Vector u, Vector v) {
return (dot(u, v) > 0);
}
bool down(Vector u, Vector v) {
return (dot(u, v) < 0);
}
ll dr(Vector u, Point Vi, Point Vj) {
return dot(u, make_Vector(Vi, Vj)); // direction sign of (Vi-Vj)
}
bool above(Vector u, Point Vi, Point Vj) {
return (dr(u, Vi, Vj) > 0); // true if Vi is above Vj
}
bool below(Vector u, Point Vi, Point Vj) {
return (dr(u, Vi, Vj) < 0); // true if Vi is below Vj
}
/*
direction vector, CCW set of polygon points, were [n]==[0]
and n - the number of actual distint points
RETURNS the maximum point in that direction idx
in logn time
*/
int polyMax_2D(Vector dir_vector, vector<Point>& poly_points, int n) {
int point_a_idx, point_b_idx, point_c_idx;
Vector edge_a_vector, edge_c_vector;
int is_up_edgeA, is_up_edgeC;
point_a_idx = 0;
point_b_idx = n;
edge_a_vector = make_Vector(poly_points[1], poly_points[0]);
is_up_edgeA = up(dir_vector, edge_a_vector);
if (!is_up_edgeA && !above(dir_vector, poly_points[n - 1], poly_points[0])) return 0;
while(1) {
point_c_idx = (point_a_idx + point_b_idx) >> 1;
edge_c_vector = make_Vector(poly_points[point_c_idx + 1], poly_points[point_c_idx]);
is_up_edgeC = up(dir_vector, edge_c_vector);
if (!is_up_edgeC && !above(dir_vector, poly_points[point_c_idx - 1], poly_points[point_c_idx])) return point_c_idx;
if (is_up_edgeA)
if (!is_up_edgeC) point_b_idx = point_c_idx;
else
if (above(dir_vector, poly_points[point_a_idx], poly_points[point_c_idx])) point_b_idx = point_c_idx;
else point_a_idx = point_c_idx, edge_a_vector = edge_c_vector, is_up_edgeA = is_up_edgeC;
else
if (is_up_edgeC) point_a_idx = point_c_idx, edge_a_vector = edge_c_vector, is_up_edgeA = is_up_edgeC;
else
if (below(dir_vector, poly_points[point_a_idx], poly_points[point_c_idx])) point_b_idx = point_c_idx;
else point_a_idx = point_c_idx, edge_a_vector = edge_c_vector, is_up_edgeA = is_up_edgeC;
if (point_b_idx <= point_a_idx + 1) return -1;
}
return -1;
}
int halfplane(Point p, ll a, ll b, ll c) {
ll res = a*p.X + b*p.Y - c;
if (res > 0)
return 1;
else if (res == 0)
return 0;
else
return -1;
}
int doesIntersect(ll a, ll b, ll c, v<pll> &hull) {
if (hull.size()-1 == 1) {
int hp = halfplane(hull[0], a, b, c);
return hp;
}
else if (hull.size() - 1 == 2) {
int hp = halfplane(hull[0], a, b, c);
int hp2 = halfplane(hull[1], a, b, c);
if (hp == 0 || halfplane(hull[1], a, b, c) != hp)
return 0;
return hp;
}
Point extr1, extr2;
extr1 = hull[polyMax_2D(make_pair(a, b), hull, hull.size() - 1)];
extr2 = hull[polyMax_2D(make_pair(-a, -b), hull, hull.size() - 1)];
int hp = halfplane(extr1, a, b, c);
if (hp == 0 || halfplane(extr2, a, b, c) != hp)
return 0;
return hp;
}
int N, M;
v<pll> cHull, pHull;
int intersect(int i, int j) { // return 0 i->j intersects with pepper hull, 1, -1 = halfplane pepper hull is on,
ll xi = cHull[i].first, yi = cHull[i].second, xj = cHull[j].first, yj = cHull[j].second;
ll A = yi - yj;
ll B = xj - xi;
ll C = (xj - xi)*yi - (yj - yi)*xi;
return doesIntersect(A, B, C, pHull);
}
void input() {
cin >> N;
cHull.resize(N);
FOR(i, 0, N) cin >> cHull[i].first >> cHull[i].second;
cHull = convex_hull(cHull);
cin >> M;
pHull.resize(M);
FOR(i, 0, M) cin >> pHull[i].first >> pHull[i].second;
if (pHull.size() > 3)
pHull = convex_hull(pHull);
pHull.push_back(pHull[0]);
//for (pll a : pHull)
// cout << a.first << " " << a.second << "\n";
}
DynamicArea da;
int main() {
io();
input();
da.init(cHull[0]);
ll ans = 0;
for (int i = 0, j = 0; i < N; i++) {
int correct = intersect(i, (i + 1) % N);
while (((j + 1) % N) != ((i - 1 + N) % N) && intersect(i, (j + 1) % N) == correct){
j = (j + 1) % N;
da.push_back(cHull[j]);
}
// cout << i << " to " << j << "\n";
if (i != j && ((i + 1) % N) != j) {
// cout << da.query() << "\n";
maxx(ans, da.query());
}
da.pop_front();
}
cout << ans << "\n";
return 0;
}
Compilation message
sir.cpp: In function 'int doesIntersect(ll, ll, ll, std::vector<std::pair<long long int, long long int> >&)':
sir.cpp:176:7: warning: unused variable 'hp2' [-Wunused-variable]
int hp2 = halfplane(hull[1], a, b, c);
^~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
376 KB |
Output is correct |
| 2 |
Correct |
2 ms |
432 KB |
Output is correct |
| 3 |
Correct |
2 ms |
432 KB |
Output is correct |
| 4 |
Correct |
2 ms |
432 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
608 KB |
Output is correct |
| 2 |
Correct |
3 ms |
736 KB |
Output is correct |
| 3 |
Correct |
6 ms |
904 KB |
Output is correct |
| 4 |
Correct |
3 ms |
904 KB |
Output is correct |
| 5 |
Correct |
3 ms |
904 KB |
Output is correct |
| 6 |
Correct |
3 ms |
936 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
304 ms |
13556 KB |
Output is correct |
| 2 |
Correct |
282 ms |
13556 KB |
Output is correct |
| 3 |
Correct |
236 ms |
13556 KB |
Output is correct |
| 4 |
Correct |
64 ms |
13556 KB |
Output is correct |
| 5 |
Correct |
219 ms |
13556 KB |
Output is correct |
| 6 |
Correct |
167 ms |
13556 KB |
Output is correct |
