/in/foo.c: In function 'main':
/in/foo.c:4:2: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
  scanf("%d",&n);
  ^~~~~
/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:11:7: error: 'i' undeclared (first use in this function)
   for(i=0;i<n;i++)
       ^
/in/foo.c:11:7: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:20:3: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
   else 
   ^~~~
/in/foo.c:26:4: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else'
    s++;
    ^
/in/foo.c:34:3: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
   printf("%d",max);
   ^~~~~~
/in/foo.c:34:3: warning: incompatible implicit declaration of built-in function 'printf'
/in/foo.c:34:3: note: include '<stdio.h>' or provide a declaration of 'printf'