operation.c

#include <math.h>
#include <stdio.h>
void p4_1_a()
{
  double y;
  int x;
  scanf("%d", &x);
  y = (x > 0  && x < 2) ? (cos(x) * cos(x)) : (1 - sin(x*x));
  printf("%.5lf\n", y);
}

void p4_1_v()
{
  int a, b, x, y;
  scanf("%d %d", &a, &b);
  a > b ? (x = a, y = b): (x = b, y = a);
  printf("%d %d\n", x, y);
}

void p4_1_d()
{
  int x, y, z;
  scanf("%d %d", &x, &y);
  z = x < 0 ? (x > y ? x: y) : (x < y ? x: y);
  printf("%d\n", z);
}

void p4_5()
{
  int w;
  scanf("%d", &w);
  if (1 / tan(w) < 0.5)
    printf("%d\n", -w);
  else 
  if (w == 0)
    printf("%d\n", w = 1); 
}

int p4_9()
{
  int a, b, c, x;
  a = b = 1;
  c = 0;
  x = a ? b : c;
  return x;
}

void p4_20()
{
  int i, a, b;
  b = 1;
  scanf("%d", &a);
  for (i = 1; a == 0; i++)
  {
    scanf("%d", &a);
    b *= a;
  }
  printf("%.5lf\n", (double)(b / i));
}

int main()
{
  p4_1_a(); 
  p4_1_v();
  p4_1_d();
  p4_5();
  p4_9();
  p4_20();
  return 0;
}