Czy ArrayList jest szybsze od LinkedList? #3

int elements = 2000000;
int tries = 100;
String values[] = new String[elements];
IntStream.range(0, elements).forEach( el -> { values[el]=el+""; } );
  
long t0 = System.currentTimeMillis();
IntStream.range(0, tries).parallel().forEach( i -> {
 ArrayList al = new ArrayList();
 IntStream.range(0, elements).parallel().forEach( j -> { al.add(values[j]); } );
});  
  
long t1= System.currentTimeMillis();
IntStream.range(0, tries).parallel().forEach( i -> {
 LinkedList ll = new LinkedList();
 IntStream.range(0, elements).parallel().forEach( j -> { ll.add(values[j]); } );
});   
  
  
long t2 = System.currentTimeMillis();
System.out.println("Add to ArrayList: "+(t1-t0)/tries+" ms avg, cnt="+elements+", tries="+tries);
System.out.println("Add to LinkedList: "+(t2-t1)/tries+" ms avg, cnt="+elements+", tries="+tries);

--
Add to ArrayList: 18 ms avg, cnt=2000000, tries=100
Add to LinkedList: 77 ms avg, cnt=2000000, tries=100

Czy ArrayList jest szybsze od LinkedList? #2

ArrayList al = new ArrayList<>();
for (int j=0; j < elements; j++)
 al.add(new Long(j));
LinkedList ll = new LinkedList<>();
for (int j=0; j < elements; j++)
  ll.add(new Long(j));
int indices[] = new int[elements / 100];
Random r = new Random(19700101);
for (int i=0; i < indices.length; i++) {
 indices[i] = r.nextInt(indices.length);
}
 
t0 = System.currentTimeMillis();
BigDecimal sum = new BigDecimal(0);
for (int i=0; i < indices.length; i++) {
 sum.add( new BigDecimal(al.get(indices[i])) );
}
t1 = System.currentTimeMillis();
sum = new BigDecimal(0);
for (int i=0; i < indices.length; i++) {
 sum.add( new BigDecimal(ll.get(indices[i])) );
}
t2 = System.currentTimeMillis();
  
System.out.println("Access ArrayList: "+(t1-t0)+" ms, cnt="+elements+", tries="+indices.length);
System.out.println("Access LinkedList: "+(t2-t1)+" ms, cnt="+elements+", tries="+indices.length);

--
Access ArrayList: 12 ms, cnt=2000000, tries=20000
Access LinkedList: 371 ms, cnt=2000000, tries=20000

Czy ArrayList jest szybsze od LinkedList?

int elements = 1000000;
int tries = 100;
String values[] = new String[elements];
for (int k=0; k < elements; k++) {
 values[k] = String.valueOf(k).intern();
}
  
long t0 = System.currentTimeMillis();
for (int i=0; i < tries; i++) {
 ArrayList al = new ArrayList();
 for (int j=0; j < elements; j++)
  al.add(values[j]);
}
  
long t1= System.currentTimeMillis();
for (int i=0; i < tries; i++) {
 LinkedList ll = new LinkedList();
 for (int j=0; j < elements; j++)
  ll.add(values[j]);
}
  
long t2 = System.currentTimeMillis();
System.out.println("Add to ArrayList: "+(t1-t0)/100+" ms avg, cnt="+elements+", tries="+tries);
System.out.println("Add to LinkedList: "+(t2-t1)/100+" ms avg, cnt="+elements+", tries="+tries);

--
Add to ArrayList: 33 ms avg, cnt=2000000, tries=100
Add to LinkedList: 51 ms avg, cnt=2000000, tries=100

Add to ArrayList: 18 ms avg, cnt=1000000, tries=100
Add to LinkedList: 12 ms avg, cnt=1000000, tries=100