Submission #72021

#	Time	Username	Problem	Language	Result	Execution time	Memory
72021		BBBSNG (#118)	Hill Reconstruction (FXCUP3_hill)	C++11	100 / 100	555 ms	85468 KiB

hill

#include <bits/stdc++.h>
#define rf(x) (x)=0;while(*p<48)p++;while(47<*p)(x)=((x)<<3)+((x)<<1)+(*p++&15);
//#define rf(x) (x)=0;while(*p<48)im=*p=='-';while(47<*p)(x)=((x)<<3)+((x)<<1)+(*p++&15);if(im)(x)=-(x);
#define pb push_back
#define eb emplace_back
#define sz(V) ((int)(V).size())
#define allv(V) ((V).begin()),((V).end())
#define befv(V) ((V)[(sz(V)-2)])
#define sorv(V) sort(allv(V))
#define revv(V) reverse(allv(V))
#define univ(V) (V).erase(unique(allv(V)),(V).end())
#define clv(V) (V).clear()
#define upmin(a,b) (a)=min((a),(b))
#define upmax(a,b) (a)=max((a),(b))
#define rb(x) ((x)&(-(x)))
#define cb(x) (x)=(!(x))
#define INF (0x3f3f3f3f)
#define INFLL (0x3f3f3f3f3f3f3f3fll)
#define INFST (0x7f7f7f7f)
#define INFLLST (0x7f7f7f7f7f7f7f7fll)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, ll> pil;
typedef pair<ll, int> pli;
typedef pair<ld, ld> pdd;
typedef complex<ld> base;
const ld EPS = (ld)1e-7;
const ld PI = acos(0) * 2;
bool isZero(const ld& x) { return abs(x) <= EPS; }
int sign(const ld& x) { return isZero(x) ? 0 : (0 < x ? 1 : -1); }
ll gcd(ll a, ll b) { for(;b;a%=b,swap(a,b)){} return abs(a); }
pll operator + (const pll& a, const pll& b) { return pll(a.first+b.first, a.second+b.second); }
pll operator - (const pll& a, const pll& b) { return pll(a.first-b.first, a.second-b.second); }
pll operator * (const pll& a, const ll& b) { return pll(a.first*b, a.second*b); }
ll operator * (const pll& a, const pll& b) { return a.first*b.second - b.first*a.second; }
ll ccw(const pll& a, const pll& b, const pll& c) { return a*b + b*c + c*a; }
void fg(vector<int> G[], int a, int b) { G[a].pb(b); G[b].pb(a); }
void fg(vector<pii> G[], int a, int b, int c) { G[a].pb({b, c}); G[b].pb({a, c}); }

const int MAXN = 300005;

inline void answer(ll x, ll y) {
	ll t = gcd(x, y);
	if(t) { x /= t; y /= t; }
	if(!y) x = 1;
	printf("%lld/%lld\n", y, x);
	exit(0);
}

struct NOD {
	NOD() : l(NULL), r(NULL), isDead(false) {}
	NOD *l, *r;
	ll x, y;
	bool isDead;
	
	pll f() { return pll(x, y); }
} *rt;

struct LNE {
	LNE(ll dx, ll dy, NOD *p) : dx(dx), dy(dy), p(p) {}
	ll dx, dy;
	NOD *p;

	bool operator < (const LNE &t) const {
		return dy * t.dx < dx * t.dy;
	}
};

priority_queue<LNE> PQ;

ll X[MAXN], Y[MAXN];

int N; ll C;

int main() {
	ios::sync_with_stdio(false);

	rt = new NOD();
	rt -> isDead = true;

	{
		NOD *p = rt;
		cin >> N >> C; C <<= 1;
		for(int i = 1; i <= N; i++) cin >> X[i];
		for(int i = 1; i <= N; i++) cin >> Y[i];
		for(int i = 1; i <= N; i++) {
			ll x = X[i], y = Y[i];
			NOD *t = new NOD();
			t -> x = x; t -> y = y;
			p -> r = t;
			t -> l = p;
			p = t;
		}
	}

	{
		NOD *p = rt -> r;
		for(;;) {
			if(!(p -> r)) break;
			PQ.push(LNE((p -> r -> x) - (p -> x), (p -> r -> y) - (p -> y), p));
			p = p -> r;
		}
	}

	for(; !PQ.empty() && 0 <= C;) {
		NOD *p = PQ.top().p;
		ll dx = PQ.top().dx, dy = PQ.top().dy;
		PQ.pop();
		if(p -> isDead) continue;
		if(!(p -> r) || p -> r -> isDead) continue;
		if(dx != (p -> r -> x) - (p -> x) || dy != (p -> r -> y) - (p -> y)) continue;
		if(p -> l == rt) answer(dx, dy);
		ll area = abs(ccw(p -> l -> f(), p -> f(), p -> r -> f()));
		if(C < area) answer(dx, dy);
		C -= area;

		p -> r -> l = p -> l;
		p -> l -> r = p -> r;
		dx = (p -> r -> x) - (p -> l -> x);
		dy = (p -> r -> y) - (p -> l -> y);
		p -> isDead = true;
		PQ.push(LNE(dx, dy, p -> l));
	}
	for(; !PQ.empty();) {
		NOD *p = PQ.top().p;
		ll dx = PQ.top().dx, dy = PQ.top().dy;
		PQ.pop();
		if(p -> isDead) continue;
		if(!(p -> r) || p -> r -> isDead) continue;
		if(dx != (p -> r -> x) - (p -> x) || dy != (p -> r -> y) - (p -> y)) continue;
		answer(dx, dy);
	}
	return 0;
}

• Subtask 1: 32 / 32
• Subtask 2: 68 / 68