Submission #1000741

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Source Code Expand

#include <iostream>
#include <fstream>
#include <set>
#include <map>
#include <string>
#include <vector>
#include <bitset>
#include <algorithm>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <cassert>
#include <queue>

#define mp make_pair
#define pb push_back


typedef long long ll;
typedef long double ld;

using namespace std;
struct point {
	ld x, y;
	point(ld X = 0, ld Y = 0) {
		x = X, y = Y;
	}
	point operator-(point a) {
		return point(x - a.x, y - a.y);
	}
	point operator+(point a) {
		return point(x + a.x, y + a.y);
	}
	ld len() {
		return sqrt(x * x + y * y);
	}
	ld operator^(point a) {
		return x * a.x + y * a.y;
	}
	ld operator*(point a) {
		return x * a.y - y * a.x;
	}
};

point nm(point a) {
	ld l = a.len();
	a.x /= l;
	a.y /= l;
	return a;
}

ld get(point a, point b, point c, ld r) {
	a = a - b;
	c = c - b;
	a = nm(a);
	c = nm(c);
	c = a + c;
	return r * (a ^ c) / (a * c);
}

point pp[100];


int main() {
	for (int i = 0; i < 3; ++i)
		cin >> pp[i].x >> pp[i].y;
	pp[3] = pp[0];
	pp[4] = pp[1];
	pp[5] = pp[2];
	ld l = 0;
	ld r = 2000;
	for (int it = 0; it < 300; ++it) {
		ld m = (l + r) / 2;
		int fl = 0;
		for (int i = 1; i <= 3; ++i) {
			if (get(pp[i - 1], pp[i], pp[i + 1], m) + 2 * m + get(pp[i], pp[i + 1], pp[i + 2], m) <= (pp[i + 1] - pp[i]).len())
				fl = 1;
		}
		if (fl)
			l = m;
		else
			r = m;
	}
	cout.setf(ios::fixed);
	cout.precision(20);
	cout << l << "\n";
	return 0;
}

Submission Info

Judge Result