ex1-1.c

/* code: ex1-1.c   (v1.20.00) */
#include <stdio.h>

int main () {
  printf ("The Open University of Japan\n");

  return 0;
}

ex1-2.c

/* code: ex1-2.c   (v1.20.00) */
#include <stdio.h>

int main () {
  int a;
  printf ("Enter an integer: ");
  scanf ("%d", &a);
  printf ("The integer you entered was %d.\n", a);

  return 0;
}

ex1-3.c

/* code: ex1-3.c   (v1.20.00) */
#include <stdio.h>

int main () {
  char a;
  short b;
  int c;
  long d;
  float e;
  double f;
  printf ("char:   %zd byte(s)\n", sizeof (a));
  printf ("short:  %zd byte(s)\n", sizeof (b));
  printf ("int:    %zd byte(s)\n", sizeof (c));
  printf ("long:   %zd byte(s)\n", sizeof (d));
  printf ("float:  %zd byte(s)\n", sizeof (e));
  printf ("double: %zd byte(s)\n", sizeof (f));

  return 0;

}

ex1-4.c

/* code: ex1-4.c   (v1.20.00) */
#include <stdio.h>

int main () {
  int a, b, c;
  a = 10;
  b = 3;
  c = 0;
  printf ("a=%d\n", a);
  printf ("b=%d\n\n", b);
  c = a + b;
  printf ("a + b = %d\n", c);
  c = a - b;
  printf ("a - b = %d\n", c);
  c = a * b;
  printf ("a * b = %d\n", c);
  c = a / b;
  printf ("a / b = %d\n", c);
  c = a % b;
  printf ("a %% b = %d\n", c);

  return 0;
}

ex1-5.c

/* code: ex1-5.c   (v1.20.00) */
#include <stdio.h>
#include <math.h>

int main () {
  double x, y, z;
  x = 30.0;
  y = 3.0;
  z = 0.0;
  printf ("x=%f\n", x);
  printf ("y=%f\n\n", y);
  z = pow (x, y);
  printf ("pow(x,y) = %f\n", z);

  return 0;
}

ex1-6.c

/* code: ex1-6.c   (v1.20.00) */
#include <stdio.h>
#include <math.h>

int main () {
  float celsius, fahrenheit;

  celsius = 36.5;
  fahrenheit = (9.0 / 5.0) * celsius + 32.0;
  printf ("%f(Celsius) = %f(Fahrenheit)\n", celsius, fahrenheit);

  return 0;
}

ex1-7.c

/* code: ex1-7.c   (v1.20.00) */
#include <stdio.h>

int main () {
  printf ("The Open University of Japan\n");
  /* web address 
     http://www.ouj.ac.jp/  */

  // C++ style comments
  // C99 allows single-line comments

  return 0;
}

q1-1.c

/* code: q1-1.c   (v1.20.00) */
#include <stdio.h>
#include <math.h>

int main () {
  double x, y;

  x = 3.14159;
  y = 0.0;
  printf ("x=%f\n\n", x);
  y = ceil (x);
  printf ("ceil(x)  = %f\n", y);
  y = floor (x);
  printf ("floor(x) = %f\n", y);

  return 0;
}

q1-2.c

/* code: q1-2.c   (v1.20.00) */
#include <stdio.h>
#include <math.h>

int main () {
  float fx, fz;
  double dx, dz;
  long double lx, lz;

  fx = 100.00F;
  fz = sqrtf (fx);
  printf ("fx = %f\n", fx);
  printf ("sqrtf(fx) = %f\n\n", fz);

  dx = 100.00;
  dz = sqrt (dx);
  printf ("dx = %f\n", dx);
  printf ("sqrt(dx)  = %f\n\n", dz);

  lx = 100.00L;
  lz = sqrtl (lx);
  printf ("lx = %Lf\n", lx);
  printf ("sqrtl(lx) = %Lf\n\n", lz);

  return 0;
}

q1-3.c

/* code: q1-3.c   (v1.20.00) */
#include <stdio.h>
#include <math.h>

int main () {
  float fahrenheit, celsius;

  fahrenheit = 25.1;
  celsius = (5.0 / 9.0) * (fahrenheit - 32.0);
  printf ("%f(Fahrenheit) = %f(Celsius)\n", fahrenheit, celsius);

  return 0;
}