If "execution time (s)" reads 0 for one of your measured cases, I become extremely skeptical of your measurements. I get that the measurement probably just roun

If "execution time (s)" reads 0 for one of your measured cases, I become extremely skeptical of your measurements. I get that the measurement probably just rounded down but that alongside a perfectly straight horizontal line just makes me go "what's going on here? What conclusion can I draw from this other than that the algorithm is somehow O(1)?" Is the value being plotted the average time per execution? You ran each test scenario for a while, not once, I assume. It's also worth considering whether you should measure against the same dataset and value every time, or have a bunch of different ones. If it's the same dataset and value it's possible you're priming the branch predictor tables, or worse, favoring one algorithm by accident due to the layout of the data.