/in/foo.c: In function 'main':
/in/foo.c:4:2: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
  scanf("%d%d",&n1,&n2);
  ^~~~~
/in/foo.c:4:2: warning: incompatible implicit declaration of built-in function 'scanf'
/in/foo.c:4:2: note: include '<stdio.h>' or provide a declaration of 'scanf'
/in/foo.c:11:3: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
   printf("%d ",a[0]);
   ^~~~~~
/in/foo.c:11:3: warning: incompatible implicit declaration of built-in function 'printf'
/in/foo.c:11:3: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:14:4: warning: incompatible implicit declaration of built-in function 'printf'
    printf("%d ",a[i]);
    ^~~~~~
/in/foo.c:14:4: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:16:3: warning: incompatible implicit declaration of built-in function 'printf'
   printf("%d ",a[n1-1]);
   ^~~~~~
/in/foo.c:16:3: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:5:16: warning: unused variable 'k' [-Wunused-variable]
  int i,count=0,k;
                ^
/in/foo.c:5:8: warning: unused variable 'count' [-Wunused-variable]
  int i,count=0,k;
        ^~~~~