I'm working on an algorithm and I'm trying to figure out its time complexity given the operations it takes to complete a input set of specific length, I have been testing the algorithm with varying input lengths.
The results shows that every time I double the input length, it takes 4 times more operations than before to complete:
- 20 items = 1M (M=million)
- 40 items = 4M
- 80 items = 16M
- 160 items = 64M
- 320 items = 256M
- 640 items = 1024M
What is the time complexity/running time that fits better with the above results?