Given a large ArrayList and a bunch of indices - what's a good way to get a list without the elements at those indices?
Performance benchmarks are done with JMH, run'em with:
mvn clean install java -jar target/benchmarks.jar org.codefx.lab.arraylist.RemoveBenchmark Some explaining needs to go into these numbers but I'm not going to do that now (too late). 😛
Benchmark (arrayLength) (removals) Mode Cnt Score Error Units RemoveBenchmark.baseline 10_000 0 sample 424380 63.505 ± 0.222 us/op RemoveBenchmark.baseline 10_000 10 sample 435078 61.964 ± 0.216 us/op RemoveBenchmark.baseline 10_000 100 sample 430968 62.539 ± 0.202 us/op RemoveBenchmark.baseline 10_000 1_000 sample 432169 62.364 ± 0.298 us/op RemoveBenchmark.baseline 100_000 0 sample 41510 649.561 ± 2.447 us/op RemoveBenchmark.baseline 100_000 10 sample 42676 631.752 ± 2.078 us/op RemoveBenchmark.baseline 100_000 100 sample 41851 644.353 ± 2.262 us/op RemoveBenchmark.baseline 100_000 1_000 sample 41461 650.318 ± 2.550 us/op RemoveBenchmark.baseline 1_000_000 0 sample 6250 4318.081 ± 55.947 us/op RemoveBenchmark.baseline 1_000_000 10 sample 6253 4315.854 ± 48.320 us/op RemoveBenchmark.baseline 1_000_000 100 sample 6306 4279.591 ± 47.078 us/op RemoveBenchmark.baseline 1_000_000 1_000 sample 6289 4290.965 ± 52.761 us/op RemoveBenchmark.copyArrayRemove 10_000 0 sample 422433 63.808 ± 0.212 us/op RemoveBenchmark.copyArrayRemove 10_000 10 sample 363302 74.184 ± 0.235 us/op RemoveBenchmark.copyArrayRemove 10_000 100 sample 79192 75.628 ± 0.343 us/op RemoveBenchmark.copyArrayRemove 100_000 0 sample 41897 643.563 ± 2.697 us/op RemoveBenchmark.copyArrayRemove 100_000 10 sample 36363 741.439 ± 3.704 us/op RemoveBenchmark.copyArrayRemove 100_000 100 sample 24082 746.417 ± 3.579 us/op RemoveBenchmark.copyArrayRemove 1_000_000 0 sample 5934 4548.275 ± 61.058 us/op RemoveBenchmark.copyArrayRemove 1_000_000 10 sample 4058 6654.678 ± 102.694 us/op RemoveBenchmark.copyArrayRemove 1_000_000 100 sample 4135 6529.373 ± 94.918 us/op RemoveBenchmark.iterativeAt 10_000 0 sample 424924 63.429 ± 0.149 us/op RemoveBenchmark.iterativeAt 10_000 10 sample 409336 65.847 ± 0.171 us/op RemoveBenchmark.iterativeAt 10_000 100 sample 259490 103.919 ± 0.315 us/op RemoveBenchmark.iterativeAt 10_000 1_000 sample 65966 408.920 ± 1.295 us/op RemoveBenchmark.iterativeAt 100_000 0 sample 39867 676.439 ± 2.997 us/op RemoveBenchmark.iterativeAt 100_000 10 sample 36813 732.621 ± 2.605 us/op RemoveBenchmark.iterativeAt 100_000 100 sample 19385 1391.798 ± 4.587 us/op RemoveBenchmark.iterativeAt 100_000 1_000 sample 3730 7242.558 ± 31.338 us/op RemoveBenchmark.iterativeAt 1_000_000 0 sample 6145 4394.814 ± 55.932 us/op RemoveBenchmark.iterativeAt 1_000_000 10 sample 4289 6297.320 ± 93.764 us/op RemoveBenchmark.iterativeAt 1_000_000 100 sample 2089 12943.901 ± 123.726 us/op RemoveBenchmark.iterativeAt 1_000_000 1_000 sample 315 86580.338 ± 2239.426 us/op RemoveBenchmark.listIterator 10_000 0 sample 338713 79.565 ± 0.262 us/op RemoveBenchmark.listIterator 10_000 10 sample 291777 92.398 ± 0.445 us/op RemoveBenchmark.listIterator 100_000 0 sample 28322 951.927 ± 10.195 us/op RemoveBenchmark.listIterator 100_000 10 sample 23533 1145.802 ± 11.786 us/op RemoveBenchmark.listIterator 1_000_000 0 sample 2812 9677.106 ± 1049.759 us/op RemoveBenchmark.listIterator 1_000_000 10 sample 2010 13512.276 ± 1252.236 us/op RemoveBenchmark.listIterator 1_000_000 100 sample 1319 13733.767 ± 1505.709 us/op RemoveBenchmark.listIterator 1_000_000 1_000 sample 1117 13468.484 ± 1633.372 us/op RemoveBenchmark.nullifyRemove 10_000 0 sample 359501 74.971 ± 0.174 us/op RemoveBenchmark.nullifyRemove 10_000 10 sample 215591 125.113 ± 0.355 us/op RemoveBenchmark.nullifyRemove 10_000 100 sample 225774 119.462 ± 0.201 us/op RemoveBenchmark.nullifyRemove 10_000 1_000 sample 228752 117.899 ± 0.396 us/op RemoveBenchmark.nullifyRemove 100_000 0 sample 36508 738.993 ± 3.087 us/op RemoveBenchmark.nullifyRemove 100_000 10 sample 20568 1311.620 ± 5.625 us/op RemoveBenchmark.nullifyRemove 100_000 100 sample 20882 1291.816 ± 5.561 us/op RemoveBenchmark.nullifyRemove 100_000 1_000 sample 21246 1269.576 ± 3.442 us/op RemoveBenchmark.nullifyRemove 1_000_000 0 sample 5680 4751.827 ± 55.961 us/op RemoveBenchmark.nullifyRemove 1_000_000 10 sample 2585 10454.266 ± 103.232 us/op RemoveBenchmark.nullifyRemove 1_000_000 100 sample 2698 10016.958 ± 114.831 us/op RemoveBenchmark.nullifyRemove 1_000_000 1_000 sample 2725 9911.803 ± 82.370 us/op