/in/foo.cc: In function 'void BST_insert(long long int, long long int)':
/in/foo.cc:22:5: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
  if (data < tree[x])
     ^
/in/foo.cc:26:5: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
  if (data >tree[x])
     ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:112:17: error: return-statement with no value, in function returning 'int' [-fpermissive]
   printf("-1"); return ;
                 ^~~~~~
/in/foo.cc: In function 'int suc(long long int, long long int, long long int)':
/in/foo.cc:87:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int find(long long int, long long int)':
/in/foo.cc:75:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^