/in/foo.c: In function 'main':
/in/foo.c:9:25: warning: implicit declaration of function 'pow' [-Wimplicit-function-declaration]
   p = -b / (2 * a); q = pow(disc, 0.5) / (2 * a);
                         ^~~
/in/foo.c:9:25: warning: incompatible implicit declaration of built-in function 'pow'
/in/foo.c:9:25: note: include '<math.h>' or provide a declaration of 'pow'
/in/foo.c:11:1: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
 if (a = 0)
 ^~
/in/foo.c:13:4: warning: statement with no effect [-Wunused-value]
  b != 0;
  ~~^~~~
/in/foo.c:19:2: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  if (disc = 0)
  ^~
/in/foo.c:34:26: warning: format '%f' expects a matching 'double' argument [-Wformat=]
   printf("%.2f+%.2fi\n%.2f-%.2fi\n",p,k);
                          ^
/in/foo.c:34:31: warning: format '%f' expects a matching 'double' argument [-Wformat=]
   printf("%.2f+%.2fi\n%.2f-%.2fi\n",p,k);
                               ^
/in/foo.c:8:12: warning: 'b' is used uninitialized in this function [-Wuninitialized]
   disc = b * b - 4 * a * c;
          ~~^~~
/in/foo.c:8:20: warning: 'a' is used uninitialized in this function [-Wuninitialized]
   disc = b * b - 4 * a * c;
                  ~~^~~
/in/foo.c:8:24: warning: 'c' is used uninitialized in this function [-Wuninitialized]
   disc = b * b - 4 * a * c;
                  ~~~~~~^~~