3 ms·
Hmm, swaps the zero problem for a overflow/underflow one?
by mrmuagi 6y ago
Hmm, swaps the zero problem for a overflow/underflow one?
- contravariant 6y agoIf you stick to multiplication and addition then the beauty of modular arithmetic ensures that over and underflow are only a problem if your final result under/overflows. In particular you can solve the problem in this article by just subtracting the numbers from 1+2+...+n-1+n. The remainder will be your missing number (though be careful with the 1+2+...+n-1+n = n(n-1)/2 formula; division by 2 is very much not compatible with arithmetic modulo a power of 2, so divide first then multiply, or keep a running total if you want to be flexible).
- ganafagol 6y agoWorse. The zero problem does not exist if the two variables are at different memory locations. The overflow problem of this solution always exists. Plus, if a and b are at the same memory location, it suffers from the same zero problem.