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| #pragma GCC optimize("-fdelete-null-pointer-checks,inline-functions-called-once,-funsafe-loop-optimizations,-fexpensive-optimizations,-foptimize-sibling-calls,-ftree-switch-conversion,-finline-small-functions,inline-small-functions,-frerun-cse-after-loop,-fhoist-adjacent-loads,-findirect-inlining,-freorder-functions,no-stack-protector,-fpartial-inlining,-fsched-interblock,-fcse-follow-jumps,-fcse-skip-blocks,-falign-functions,-fstrict-overflow,-fstrict-aliasing,-fschedule-insns2,-ftree-tail-merge,inline-functions,-fschedule-insns,-freorder-blocks,-fwhole-program,-funroll-loops,-fthread-jumps,-fcrossjumping,-fcaller-saves,-fdevirtualize,-falign-labels,-falign-loops,-falign-jumps,unroll-loops,-fsched-spec,-ffast-math,Ofast,inline,-fgcse,-fgcse-lm,-fipa-sra,-ftree-pre,-ftree-vrp,-fpeephole2",3)
#pragma GCC target("avx", "sse2")
#define IO ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr)
#include <bits/stdc++.h>
#define maxn 800005
using namespace std;
const long double eps = 1e-8;
int sgn(long double x){
if(fabs(x) < eps) return 0;
return x > eps ? 1 : -1;
}
template<typename T> struct TP{
T x, y;
friend TP operator +(const TP &a, const TP &b){
return {a.x + b.x, a.y + b.y};
}
friend TP operator -(const TP &a, const TP &b){
return {a.x - b.x, a.y - b.y};
}
friend T operator *(const TP &a, const TP &b){
return a.x * b.x + a.y * b.y;
}
friend T operator ^(const TP &a, const TP &b){
return a.x * b.y - a.y * b.x;
}
friend bool operator ==(const TP &a, const TP &b){
return fabs(a.x - b.x) < eps && fabs(a.y - b.y) < eps;
}
int toleft(const TP &b){
auto p = (*this) ^ b;
return (p > eps) - (p < -eps);
}
T len(){
return sqrt(x * x + y * y);
}
T distance(TP &b){
return ((*this) - b).len();
}
void print(){
cout << "[Point] " << x << " " << y << '\n';
}
}; using Point = TP<long double>;
template<typename T> struct TL{
TP<T> s, e;
int relation(TP<T> &p){
int c = sgn((p - s) ^ (e - s));
if(c < 0) return 1;
if(c > 0) return 2;
return 3;
}
int linecrossseg(TL &v){
int d1 = sgn((e - s) ^ (v.s - s));
int d2 = sgn((e - s) ^ (v.e - s));
if((d1 ^ d2) == -2) return 2;
return (d1 == 0 || d2 == 0);
}
TP<T> crosspoint(TL &v){
auto a1 = (v.e - v.s) ^ (s - v.s);
auto a2 = (v.e - v.s) ^ (e - v.s);
return {(s.x * a2 - e.x * a1) / (a2 - a1), (s.y * a2 - e.y * a1) / (a2 - a1)};
}
}; using Line = TL<long double>;
struct ConvexHull{
int siz;
long double alen;
vector<Point> p; vector<Line> l;
vector<long double> len;
void build(vector<Point> &o){
auto nxt = [&](int i){ return i == p.size() - 1 ? 0 : i + 1; };
auto pre = [&](int i){ return i == 0 ? p.size() - 1 : i - 1; };
siz = o.size();
for(int i = 0; i < siz; i++) p.push_back(o[i]);
for(int i = 0; i < siz; i++){
l.push_back({o[i], o[nxt(i)]});
len.push_back(o[i].distance(o[nxt(i)]));
alen += len.back();
}
}
}B, S;
int n, m;
vector<Point> iB, iS;
long double querySum(int L, int R, vector<long double> &sum){
if(R < L) return 0;
if(L == 0) return sum[R];
return sum[R] - sum[L - 1];
}
long double solve(){
auto nxt = [&](int i, vector<Line> &p){ return i == p.size() - 1 ? 0 : i + 1; };
auto pre = [&](int i, vector<Line> &p){ return i == 0 ? p.size() - 1 : i - 1; };
long double exp = 0;
vector<long double> sum, val = B.len; vector<Line> out = B.l, in = S.l;
val.insert(val.end(), val.begin(), val.end());
sum.resize(val.size());
partial_sum(val.begin(), val.end(), sum.begin());
int siz = in.size(), sizo = out.size(), L = 0, R = 0;
for(int i = 0; i < siz; i++){
long double result = 0;
while(!in[i].linecrossseg(out[L]) ||
(in[i].linecrossseg(out[L]) == 1 && in[i].crosspoint(out[L]) == out[L].e)) L = nxt(L, out);
while(!in[i].linecrossseg(out[R]) ||
(in[i].linecrossseg(out[R]) == 1 && in[i].crosspoint(out[R]) == out[R].e) || L == R) R = nxt(R, out);
Point crossL = in[i].crosspoint(out[L]);
Point crossR = in[i].crosspoint(out[R]);
if((crossR - crossL) * (in[i].e - in[i].s) > 0){
int FL = L, FR = R;
if(FL > FR) FR += sizo;
long double nowLen = querySum(FL + 1, FR - 1, sum) +
crossL.distance(out[L].e) +
crossR.distance(out[R].s);
result += nowLen * S.len[i];
} else{
int FL = R, FR = L;
if(FL > FR) FR += sizo;
long double nowLen = querySum(FL + 1, FR - 1, sum) +
crossR.distance(out[R].e) +
crossL.distance(out[L].s);
result += nowLen * S.len[i];
}
exp += result;
}
return exp / B.alen;
}
signed main(void)
{
scanf("%d %d", &n, &m);
for(int i = 1; i <= n; i++){
long double x, y;
scanf("%Lf %Lf", &x, &y);
iB.push_back({x, y});
}
for(int i = 1; i <= m; i++){
long double x, y;
scanf("%Lf %Lf", &x, &y);
iS.push_back({x, y});
}
B.build(iB); S.build(iS);
printf("%.15Lf\n", solve());
return 0;
}
|
