Question

As usually reading through stuff I got this question in mind.
If I have a character array initialization like below , what will be the time complexity for this statement?

char array[] = {'a','b','c','d','e'};

Will it actually execute 5 time to assign each variable; as we do in loop. If assumption is true why is it so?

Answer 1

depending on where the declaration occurs and the compiler’s intelligence, it could be O(1) or O(n). some cases:

1. global declaration, smart compiler would put it in data section, already initialized, thus O(1)
2. local declaration, if proven to be read only by a smart compiler, it could be like above, plus a reference assignment to the array, still O(1) however
3. local declaration, read write, could be storage allocation + 5 assignment (clearly O(n) OR storage allocation + array data copy (like 2, but the data gets copied instead of only the reference). the latter could be O(1) with vectorized code (well… more or less because it depends on quite a lot of things)