标签：setname long logs nts == next alt getname collect
为了方便 ，我把bean写成了内部类
测试结论 ，快速排序吊打compare排序 ,可以自行测试
1 //测试调用 2 public static void main(String[] args) { 3 List<Student> list = new ArrayList<Student>(); 4 new test().add(list); 5 //记录旧数据 确定俩次排序使用的是同一数据 6 List<Student> stus = new ArrayList<Student>(); 7 stus = list; 8 9 long aa = new Date().getTime(); 10 quickSort(list, 0, list.size() - 1); 11 System.out.println("快速排序" + (new Date().getTime() - aa)); 12 13 System.out.println(); 14 15 aa = new Date().getTime(); 16 Collections.sort(stus, new IndexComparator()); 17 System.out.println("compare排序" + (new Date().getTime() - aa)); 18 }
1 //创建100w条学生 2 public void add(List<Student> list) { 3 while (list.size() < 1000000) { 4 list.add(new Student((new Random().nextInt(1000000) + 1), "")); 5 } 6 }
1 //快速排序 2 public static void quickSort(List<Student> data, int left, int right) { 3 Student temp = new Student(); 4 int f, rtemp, ltemp; 5 ltemp = left; 6 rtemp = right; 7 f = data.get((left + right) / 2).getCount(); 8 while (ltemp < rtemp) { 9 while (data.get(ltemp).getCount() < f) { 10 ++ltemp; 11 } 12 while (data.get(rtemp).getCount() > f) { 13 --rtemp; 14 } 15 if (ltemp <= rtemp) { 16 temp = data.get(ltemp); 17 data.set(ltemp, data.get(rtemp)); 18 data.set(rtemp, temp); 19 --rtemp; 20 ++ltemp; 21 } 22 } 23 if (left == rtemp) { 24 ltemp++; 25 } 26 if (left < rtemp) { 27 quickSort(data, rtemp + 1, right); 28 } 29 if (ltemp < right) { 30 quickSort(data, rtemp + 1, right); 31 } 32 }
1 /** 2 * compare排序 3 */ 4 static class IndexComparator implements Comparator<Student> { 5 6 @Override 7 public int compare(Student o1, Student o2) { 8 Integer sort1 = o1.getCount(); 9 Integer sort2 = o2.getCount(); 10 return sort1.compareTo(sort2); 11 } 12 }
实体Student
1 static class Student { 2 private int count; 3 4 private String name; 5 6 public int getCount() { 7 return count; 8 } 9 10 public Student() { 11 super(); 12 // TODO Auto-generated constructor stub 13 } 14 15 public Student(int count, String name) { 16 super(); 17 this.count = count; 18 this.name = name; 19 } 20 21 public void setCount(int count) { 22 this.count = count; 23 } 24 25 public String getName() { 26 return name; 27 } 28 29 public void setName(String name) { 30 this.name = name; 31 } 32 }
标签：setname long logs nts == next alt getname collect
原文地址：http://www.cnblogs.com/bynb/p/6749348.html
