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106 lines
3.7 KiB
C++

#define _CRT_SECURE_NO_WARNINGS
#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
#include <bits/stdc++.h>
using namespace std;
#define CRP(t, x) const t &x
#define OPX(op, t, x) operator op(CRP(t, x))
#define OPL(t, x) bool OPX(<, t, x) const
#define FIL(x, v) memset(x, v, sizeof(x))
#define CLR(x) FIL(x, 0)
#define NE1(x) FIL(x, -1)
#define INF(x) FIL(x, 0x3f)
#ifndef _DEBUG
#define _DEBUG 0
#endif // !_DEBUG
#define IFD if (_DEBUG)
typedef long long ll, i64;
constexpr double eps = 1e-8;
int sgn(double x)
{
if (x > eps)
return 1;
if (x < -eps)
return -1;
return 0;
}
template <typename T>
using enable_if_arithmetic = typename enable_if<is_arithmetic<T>::value>::type;
template <typename T>
using enable_if_integral = typename enable_if<is_integral<T>::value>::type;
template <typename T, typename = enable_if_arithmetic<T>>
struct Point
{
T x, y;
Point OPX(-, Point, rhs) const { return {x - rhs.x, y - rhs.y}; }
T OPX(*, Point, rhs) const { return x * rhs.x + y * rhs.y; }
T OPX (^, Point, rhs) const { return x * rhs.y - y * rhs.x; }
T len2() const { return x * x + y * y; }
double len() const { return sqrt(len2()); }
};
template <typename T>
struct Line
{
Point<T> s, e;
T len2() const { return (s - e).len2(); }
double len() const { return (s - e).len(); }
bool contains(CRP(Point<T>, p)) const { return sgn((s - p) ^ (e - p)) == 0 && sgn((s - p) * (e - p)) <= 0; }
};
#define Point Point<double>
#define Line Line<double>
double area(CRP(Point, p1), CRP(Point, p2), CRP(Point, p3))
{
return abs((p3 - p1) ^ (p2 - p1));
}
int main2()
{
Point p[3], e;
while (~scanf("%lf%lf%lf%lf%lf%lf%lf%lf", &p[0].x, &p[0].y, &p[1].x, &p[1].y, &p[2].x, &p[2].y, &e.x, &e.y))
{
Line ls[3] = {{p[1], p[2]}, {p[0], p[2]}, {p[0], p[1]}};
bool flag = true;
for (int i = 0; i < 3 && flag; i++)
if (ls[i].contains(e))
{
int l = (i + 2) % 3, r = (i + 1) % 3;
int near = (e - p[l]).len2() < (e - p[r]).len2() ? l : r;
int other = l + r - near;
double len = ls[i].len() * ls[near].len() / 2 / (e - p[other]).len();
double fulllen = ls[near].len();
Point dif = p[i] - p[other];
printf("%.12lf %.12lf\n", p[other].x + dif.x * len / fulllen, p[other].y + dif.y * len / fulllen);
if (sgn(area(p[other], e, {p[other].x + dif.x * len / fulllen, p[other].y + dif.y * len / fulllen}) * 2 - area(p[0], p[1], p[2])))
return -1;
flag = false;
}
if (flag)
puts("-1");
}
return 0;
}
int main()
{
Point p[3], e;
while (~scanf("%lf%lf%lf%lf%lf%lf%lf%lf", &p[0].x, &p[0].y, &p[1].x, &p[1].y, &p[2].x, &p[2].y, &e.x, &e.y))
{
Line ls[3] = {{p[1], p[2]}, {p[0], p[2]}, {p[0], p[1]}};
bool flag = true;
for (int i = 0; i < 3 && flag; i++)
if (ls[i].contains(e))
{
int l = (i + 2) % 3, r = (i + 1) % 3;
int near = (e - p[l]).len2() < (e - p[r]).len2() ? l : r;
int other = l + r - near;
double len = sqrt(ls[i].len2() * ls[near].len2() / 4 / (e - p[other]).len2());
double fulllen = ls[near].len();
Point dif = p[i] - p[other];
printf("%.12lf %.12lf\n", p[other].x + dif.x * len / fulllen, p[other].y + dif.y * len / fulllen);
if (sgn(area(p[other], e, {p[other].x + dif.x * len / fulllen, p[other].y + dif.y * len / fulllen}) * 2 - area(p[0], p[1], p[2])))
return -1;
flag = false;
}
if (flag)
puts("-1");
}
return 0;
}