package collection;
import character.Hero;
import java.util.*;
public class TestCollection {
public static void main(String[] args) {
List<Integer> l;
l = new ArrayList<>();
insertFirst(l,"ArrayList");
insertLast(l,"ArrayList");
insertMidum(l,"ArrayList");
modify(l,"ArrayList");
l = new LinkedList<>();
insertFirst(l,"LinkedList");
insertLast(l,"LinkedList");
insertMidum(l,"LinkedList");
modify(l,"LinkedList");
}
private static void insertFirst(List<Integer> l,String type){
int total= 100*1000;
final int number = 5;
long start = System.currentTimeMillis();
for(int i=0;i<total;i++){
l.add(0,number);
}
long end = System.currentTimeMillis();
System.out.printf("在%s最前面插入%d数据,总共耗时%d毫秒%n",type,total,(end-start));
System.out.println();
}
private static void insertLast(List<Integer> l,String type){
int total = 100*1000;
final int number = 5;
long start = System.currentTimeMillis();
for(int i=0;i<total;i++){
l.add(number);
}
long end = System.currentTimeMillis();
System.out.printf("在%s最后面插入%d数据,总共耗时%d毫秒%n",type,total,(end-start));
System.out.println();
}
private static void insertMidum(List<Integer> l,String type){
int total = 100*1000;
final int number = 5;
long start = System.currentTimeMillis();
for(int i = 0;i<total;i++){
l.add(l.size()/2,number);
}
long end = System.currentTimeMillis();
System.out.printf("在%s中间插入%d数据,总共耗时%d毫秒%n",type,total,(end-start));
}
private static void modify(List<Integer> l,String type){
int total = 100*1000;
int index = total/2;
final int number = 5;
for(int i=0;i<total;i++){
l.add(number);
}
long start = System.currentTimeMillis();
for(int i=0;i<total;i++){
int n = l.get(index);
n++;
l.set(index,n);
}
long end = System.currentTimeMillis();
System.out.printf("%s总长度是%d,定位到第%d个数据,取出来加1,在放回去,重复%d边,总共耗时%d毫秒%n",type,total,index,total,(end-start));
System.out.println();
}
}
RESULT:
在ArrayList最前面插入100000数据,总共耗时508毫秒
在ArrayList最后面插入100000数据,总共耗时4毫秒
在ArrayList中间插入100000数据,总共耗时1487毫秒
ArrayList总长度是100000,定位到第50000个数据,取出来加1,在放回去,重复100000边,总共耗时6毫秒
在LinkedList最前面插入100000数据,总共耗时4毫秒
在LinkedList最后面插入100000数据,总共耗时3毫秒
在LinkedList中间插入100000数据,总共耗时22199毫秒
LinkedList总长度是100000,定位到第50000个数据,取出来加1,在放回去,重复100000边,总共耗时21554毫秒