/in/foo.cc:3:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:11:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    mid=lft+rgt>>1;
        ~~~^~~~
/in/foo.cc:19:22: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
  printf("%d %d",aa,bb);
                      ^
/in/foo.cc:19:22: warning: format '%d' expects argument of type 'int', but argument 3 has type 'long long int' [-Wformat=]