Submission #1000698

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Source Code Expand

#ifdef DEBUG
#define _GLIBCXX_DEBUG
#endif

#include <bits/stdc++.h>

using namespace std;

typedef long double ld;
typedef long long ll;

#ifdef DEBUG
#define eprintf(...) fprintf(stderr, __VA_ARGS__), fflush(stderr)
#else
#define eprintf(...) ;
#endif

#define pb push_back
#define mp make_pair
#define sz(x) ((int) (x).size())
#define TASK "text"

const int inf = (int) 1.01e9;
const ld eps = 1e-9;
const ld pi = acos((ld) -1);

mt19937 mrand(random_device{} ()); 

int rnd(int x) {
  return mrand() % x;
}

void precalc() {
}

struct point {
  ld x, y;

  point() {}

  point(ld _x, ld _y): x(_x), y(_y) {}

  bool read() {
    double xx, yy;
    if (scanf("%lf%lf", &xx, &yy) < 2) {
      return false;
    }
    x = xx;
    y = yy;
    return true;
  }

  point operator - (const point &p) const {
    return point(x - p.x, y - p.y);
  }

  ld operator ^ (const point &p) const {
    return x * p.y - y * p.x;
  }

  ld slen() const {
    return x * x + y * y;
  }

  ld len() const {
    return sqrt(slen());
  }
};

point a, b, c;

int read() {
  if (!a.read() || !b.read() || !c.read()) {
    return false;
  }
  return true;
}

void solve() {
  ld s = abs((b - a) ^ (c - a));
  ld ha = s / (c - b).len(), hb = s / (a - c).len(), hc = s / (b - a).len();
  ld len = max((b - a).len(), max((c - b).len(), (a - c).len()));
  ld l = 0, r = 1e4;
  for (int it = 0; it < 200; it++) {
    ld m = (l + r) / 2;
    if (m > hc - eps) {
      r = m;
    }
    ld kc = (hc - m) / hc;
    ld hb0 = hb * kc;
    if (m > hb0 - eps) {
      r = m;
    }
    ld kb = kc * (hb0 - m) / hb0;
    ld ha0 = ha * kb;
    if (m > ha0 - eps) {
      r = m;
    }
    ld ka = kb * (ha0 - m) / ha0;
    if (len * ka < 2 * m) {
      r = m;
    } else {
      l = m;
    }
  }
  printf("%.20f\n", (double) l);
}

int main() {
  precalc();
#ifdef LOCAL
  assert(freopen(TASK ".in", "r", stdin));
  assert(freopen(TASK ".out", "w", stdout));
#endif
  while (true) {
    if (!read()) {
      break;
    }
    solve();
#ifdef DEBUG
    eprintf("Time %.2f\n", (double) clock() / CLOCKS_PER_SEC);
#endif
  }
  return 0;
}

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