foo.cc: In function ‘int main()’:
foo.cc:15:25: error: ‘total’ was not declared in this scope
   15 |                         total++;
      |                         ^~~~~
foo.cc:36:29: warning: comparison of integer expressions of different signedness: ‘size_t’ {aka ‘long unsigned int’} and ‘int’ [-Wsign-compare]
   36 |         for(size_t i = 0; i < tips; i++)
      |                           ~~^~~~~~
foo.cc:40:25: error: ‘total’ was not declared in this scope
   40 |                         total++;
      |                         ^~~~~