short but for optimized - u have way too many iterations calling count and set/sum

Wouldn't think that my solution would be same as most of the people. The only thing different I did I wrapped a==b with int - for cleaner output. Cause I know that 1 == True on current test comparison

hmm, cool to find out somebody else having exactly same solution

Just fyi u don't need break if you have return. Basically in switch case scerario the reading stream going from top to bottom to facilitate that switch choice u need to leave the stream therefore usual tradition to use break - but u can also use any method of breaking out - return, process.stop etc.

And I thought I had some unorthodox solution

Wrong range. Should be 1,len(s). There is an obvious lack of edge cases.