高效删除ArrayList中的重复记录，不多说看代码

import java.util.ArrayList;
import java.util.List;
public class HighEffectDelete {
public static void main(String[] args) {
List<Integer> list = new ArrayList<Integer>();
for (int i = 0; i < 1000000; i++) {
list.add(i);
if (i % 10 == 0)
list.add(0);
}
Long start = System.currentTimeMillis();
effectiveDelete(list, 0);
//normalDelete(list, 0);
System.out.println((System.currentTimeMillis() - start));
}
public static void normalDelete(List<Integer> list, Object key) {
for (int i = list.size() - 1; i > -1; i--) {
if (key.equals(list.get(i)))
list.remove(i);
}
}
public static void effectiveDelete(List<Integer> list, Object key) {
int i = 0, j = 0, size = list.size();
while (j < size) {
Integer elem = list.get(j);
if (key.equals(elem)) {
for (j = j + 1; j < size && key.equals(list.get(j)); j++)
;
while (j < size) {
Integer o = list.get(j);
if (!key.equals(o)) {
list.set(i, o);
i++;
j++;
} else {
break;
}
}
} else {
i++;
j++;
}
}
for (int k = size - 1; k >= i; k--) {
list.remove(k);
}
}
}