/in/foo.c: In function 'main':
/in/foo.c:7:4: warning: implicit declaration of function 'sqrt' [-Wimplicit-function-declaration]
  k=sqrt(x);
    ^~~~
/in/foo.c:7:4: warning: incompatible implicit declaration of built-in function 'sqrt'
/in/foo.c:7:4: note: include '<math.h>' or provide a declaration of 'sqrt'
/in/foo.c:10:17: warning: too many arguments for format [-Wformat-extra-args]
  if(i>k) printf("Yes",x);
                 ^~~~~
/in/foo.c:11:23: warning: too many arguments for format [-Wformat-extra-args]
  else if(i<=k) printf("No",x);
                       ^~~~