I'd like to ask you a question about calculating the time complexity

for(i = 1; i < n ; i *= 2) printf("Hello"); In this case, i increases like an exponential function of 2. At this time, the time complexity is log with 2 down I think so. Namely log2(n).

for(i = 0; i < n ; i++) for(j = 1; j < n; j *=2) printf("hello") In the same case, I think it's n from the front and log to the back and down 2 as well.

Porridge n *log2(n).

To represent the time complexity, you can use an expression to represent the number of times you calculate..