Submission #4061045

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Source Code Expand

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>

using namespace std;

double calc_radius(double l, double theta1, double theta2) {
  return l / (1 / tan(theta1 / 2) + 1 / tan(theta2 / 2) + 2);
}

double calc_distance(double x1, double y1, double x2, double y2) {
  const double dx = x2 - x1, dy = y2 - y1;
  return sqrt(dx * dx + dy * dy);
}

double calc_angle(double dx1, double dy1, double dx2, double dy2) {
  const double norm1 = sqrt(dx1 * dx1 + dy1 * dy1);
  const double norm2 = sqrt(dx2 * dx2 + dy2 * dy2);
  const double inner = dx1 * dx2 + dy1 * dy2;
  return acos(inner / (norm1 * norm2));
}

int main(int argc, char *argv[]) {
  // read inputs
  double xs[3], ys[3];
  for (int i = 0; i < 3; i++) {
    scanf("%lf %lf", &xs[i], &ys[i]);
  }

  double ls[3], ts[3];
  for (int i = 0; i < 3; i++) {
    ls[i] = calc_distance(xs[(i + 1) % 3], ys[(i + 1) % 3], xs[(i + 2) % 3],
                          ys[(i + 2) % 3]);
    ts[i] = calc_angle(xs[(i + 1) % 3] - xs[i], ys[(i + 1) % 3] - ys[i],
                       xs[(i + 2) % 3] - xs[i], ys[(i + 2) % 3] - ys[i]);
    // printf("i = %d, l = %lf, t = %lf\n", i, ls[i], ts[i]);
  }

  double rs[3], ans = 0;
  for (int i = 0; i < 3; i++) {
    rs[i] = calc_radius(ls[i], ts[(i + 1) % 3], ts[(i + 2) % 3]);
    ans = max(ans, rs[i]);
  }
  printf("%.15lf\n", ans);

  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main(int, char**)’:
./Main.cpp:28:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lf %lf", &xs[i], &ys[i]);
                                     ^

Judge Result