Question

I have n of type unsigned long long
and a loop in c/c++

while( n < ULLONG_MAX ){
...
n += revert( n );
}

I need to output the last n before it goes really big, is there a way I can verify and break loop? Because all the time I get outputted big same number but less then ULLONG_MAX

Answer 1

If n is unsigned long long then n <= ULLONG_MAX is always true.

If you know that revert always returns a positive number you can check if n + revert( n ) is < n (i.e., check a wrap around). Or also check that revert(n) < ULLONG_MAX - n.