/in/foo.c: In function 'main':
/in/foo.c:11:11: warning: implicit declaration of function 'fabs' [-Wimplicit-function-declaration]
   min=min+fabs(a[j]-x);
           ^~~~
/in/foo.c:11:11: warning: incompatible implicit declaration of built-in function 'fabs'
/in/foo.c:11:11: note: include '<math.h>' or provide a declaration of 'fabs'
/in/foo.c:17:8: warning: incompatible implicit declaration of built-in function 'fabs'
    t=t+fabs(a[j]-x);
        ^~~~
/in/foo.c:17:8: note: include '<math.h>' or provide a declaration of 'fabs'