The trip is a very interesting problem, but the fact for me is that I haven't been able to solve it even after a long time. I have collected all the test cases available in the board and all except 1 test case fails and I have no idea how to solve it. Here's the failing test case:
0.01
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
The expected answer is: $0.02, while my solution says $0.01.
To me, it looks like there is some key piece in the problem statement that is missing for me to correctly figure out the answer. I also felt that arriving at my current solution was also not very straight forward. I believe that clearing up the problem statement will help people to understand it better and solve it. The problem's success rate is average probably because of this reason.
My learnings:
1. Program to use money like the way it is being by people. Do not go for floats and doubles. That will help in avoiding magic like floor, ceiling. I got this hint from Prof.Skiena's programming challenges videos. The original link seems to be dead :(
2. The way to compute average is very key to be able to get to a solution and to be able to explain it to others. What is a solution if it cannot be understood by others? What is a solution if it cannot be explained to others?