Calc

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#define PI 3.1415926535

typedef struct {
  double rad1, rad2;
} radian_t;

radian_t *radian(int, int);
double *keisan_X(double);
double *keisan_Y(double);

int main(void) {
  int theta1, theta2, i;
  double X, Y, *x, *y;
  printf("Θ１の値(deg)を入力してください: ");
  scanf("%d", &theta1);
  printf("Θ２の値(deg)を入力してください: ");
  scanf("%d", &theta2);
  radian_t *rad = radian(theta1, theta2);
  X = (cos(rad->rad1) + cos(rad->rad2)) / 2.;
  Y = (sin(rad->rad1) + sin(rad->rad2)) / 2.;
  printf("x = %f, y = %f\n", X, Y);
  x = keisan_X(X);
  y = keisan_Y(Y);
  for (i = 0; i < 4; i++) {
    printf("x[%d] = %f, y[%d] = %f\n", i, x[0], i, y[0]);
  }
  return EXIT_SUCCESS;
}

radian_t *radian(int theta1, int theta2) {
  radian_t *rad = (radian_t *) malloc(sizeof(radian_t));
  rad->rad1 = PI * theta1 / 180.;
  rad->rad2 = PI * (theta1 + theta2) / 180.;
  return rad;
}

double *keisan_X(double X) {
  int a, i;
  double XX = (0 - X) / 4.;
  double *x = (double *) malloc(4 * sizeof(double));
  for (i = 0, a = 1; i < 4; i++, a++)
    x[i] = X * a * XX;
  return x;
}

double *keisan_Y(double Y) {
  int a, i;
  double YY = (0.8 - Y) / 4.;
  double *y = (double *) malloc(4 * sizeof(double));
  for (i = 0, a = 1; i < 4; i++, a++)
    y[0] = Y + a * YY;
  return y;
}