Do running times match with O(nlogn)?
- by user472221
Hi
I have written a class(greedy strategy) that at first i used sort method which has O(nlogn)
Collections.sort(array, new
SortingObjectsWithProbabilityField());
and then i used the insert method of binary search tree which takes O(h) and h here is the tree height.
for different n ,the running time will be :
n,running time
17,515428
33,783340
65,540572
129,1285080
257,2052216
513,4299709
which I think is not correct because for increasing n , the running time should almost increase.
This method will take the running time:
Exponent = -1;
for(int n = 2;n<1000;n+=Math.pow(2,exponent){
for (int j = 1; j <= 3; j++) {
Random rand = new Random();
for (int i = 0; i < n; i++) {
Element e = new Element(rand.nextInt(100) + 1, rand.nextInt(100) + 1, 0);
for (int k = 0; k < i; k++) {
if (e.getDigit() == randList.get(k).getDigit()) {
e.setDigit(e.getDigit() + 1);
}
}
randList.add(e);
}
double sum = 0.0;
for (int i = 0; i < randList.size(); i++) {
sum += randList.get(i).getProbability();
}
for (Element i : randList) {
i.setProbability(i.getProbability() / sum);
}
//Get time.
long t2 = System.nanoTime();
GreedyVersion greedy = new GreedyVersion((ArrayList<Element>) randList);
long t3 = System.nanoTime();
timeForGreedy = timeForGreedy + t3 - t2;
}
System.out.println(n + "," + "," + timeForGreedy/3 );
exponent++;
}
thanks
