Linked Questions

1 vote
2 answers

Why don't we calculate swaps and other steps except comparison for finding time complexity of a sorting algorithm? [duplicate]

I was learning some basic sorting techniques with their complexity. However I cannot understand why only the number of comparisons are taken into account while calculating time complexity and ...
Bhushan's user avatar
  • 121
2 votes
2 answers

Why comparison is dominant time consumption for comparison-based sorting algorithms? [duplicate]

Comparison-based sorting algorithms does a number of different operations to accomplish the sorting, why comparisons are the dominant time consumption? While I understand the standard analyses of ...
user78219's user avatar
194 votes
3 answers

Is there a system behind the magic of algorithm analysis?

There are lots of questions about how to analyze the running time of algorithms (see, e.g., runtime-analysis and algorithm-analysis). Many are similar, for instance those asking for a cost analysis ...
Raphael's user avatar
  • 72k
25 votes
4 answers

How to fool the plot inspection heuristic?

Over here, Dave Clarke proposed that in order to compare asymptotic growth you should plot the functions at hand. As a theoretically inclined computer scientist, I call(ed) this vodoo as a plot is ...
Raphael's user avatar
  • 72k
6 votes
2 answers

What is the complexity of this matrix transposition?

I'm working on some exercises regarding graph theory and complexity. Now I'm asked to give an algorithm that computes a transposed graph of $G$, $G^T$ given the adjacency matrix of $G$. So basically I ...
Oxymoron's user avatar
  • 213
9 votes
2 answers

Computational complexity vs Computational cost

Is there a difference between the computational complexity and computational cost of an algorithm?
Josh3248's user avatar
  • 103
8 votes
2 answers

What constitutes one unit of time in runtime analysis?

When calculating runtime dependence on the input, what calculations are considered? For instance, I think I learned that array indexing as well as assignment statements don't get counted, why is that?
user avatar
11 votes
2 answers

Is there any standard for comparing runtimes experimentally?

My situation I am writing a paper presenting a software module I developed and I want to compare its runtime to other modules for the same task. I am aware of the drawbacks of runtime experiments, ...
Wrzlprmft's user avatar
  • 245
3 votes
1 answer

Compare asymptotic WC runtime with measured AC runtime

I have an algorithm and I determined the asymptotic worst-case runtime, represented by Landau notation. Let's say $T(n) = O(n^2)$; this is measured in number of operations. But this is the worst case,...
geasssos's user avatar
  • 161
8 votes
1 answer

What counts as an operation?

Apologies for the newbie question, but I am a bit confused about what exactly counts as a "simple operation" when working out the time complexity of an algorithm. In particular, why do we consider all ...
user85798's user avatar