In 7, out 3, in 3 - out 7. other than that? Anything goes!
/* This is a question that I was asked in an interview: Implement a function that gets an integer n and does the following:
- if n is 3 -> return 7.
- else if n is 7 -> return 3.
- otherwise return any number you like (undefined behavior).
Also describe what's the runtime and space complexity of each way.
So first I gave the trivial way of using if-else statement - and said it's O(1) run-time + space complexity. Then the interviewer said: "what if you can't use if statements (including switch-case and other if statements similarities)?"
So I suggested using bitwise operations: return n^=4. Said that it's O(1) run-time + space complexity. Then the interviewer said: "what if you can't use bitwise operations?"
So I suggested using an array like this:
int mem[8] = {-1, -1, -1, 7, -1, -1, -1, 3};
return mem[n];
Said it's O(1) run-time + space complexity, how ever it might be non-efficient if we have large numbers instead of 3 and 7.
Then the interviewer said: "what if you can't use arrays?" - and here I got stuck.
It seems like there is a fourth way... any suggestions? */
That's actually a good question. I guess that discovery does not happen with a set target in mind!
from console, install jest
npm install --save-dev jest
then you can just run the tests
npm test
if you want to benchmark use
npm run bench