分析算法时间复杂度.zip

package zy.com.datastructure; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.util.Log; import android.widget.Button; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.Iterator; import java.util.List; import java.util.Random; import butterknife.BindView; import butterknife.ButterKnife; import butterknife.OnClick; public class MainActivity extends AppCompatActivity { @BindView(R.id.sort) Button sort; @BindView(R.id.insert) Button insert; @BindView(R.id.recyclerView) RecyclerView recyclerView; private List<User> list = new ArrayList<>(); private MyAdapter adapter; private String TAG1 = "TAG1"; private String TAG2 = "TAG2"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ButterKnife.bind(this); // long startTime = System.currentTimeMillis(); //获取开始时间 // long endTime = System.currentTimeMillis(); //获取结束时间 // System.out.println("程序运行时间： " + (startTime - endTime) + "ms"); initData(); adapter = new MyAdapter(R.layout.item_recycler, list); recyclerView.setLayoutManager(new LinearLayoutManager(this)); recyclerView.setHasFixedSize(true); recyclerView.setAdapter(adapter); } private void initData() { for (int i = 0; i < 2000; i++) { Random random = new Random(); String time = String.valueOf(System.currentTimeMillis()); String name = "张" + random.nextInt(10000); list.add(new User(time, name)); } } @OnClick(R.id.sort) public void onSortClicked() { long startTime = System.currentTimeMillis(); //获取开始时间 Collections.sort(list, new TimeComparator()); // 根据时间排序 adapter.setNewData(list); long endTime = System.currentTimeMillis(); //获取结束时间 Log.i(TAG1, "Sort程序运行时间： " + (startTime - endTime) + "ms"); System.out.println("按时间排序:"); // myprint(list); } // 自定义方法：分行打印输出list中的元素 public void myprint(List<User> list) { Iterator it = list.iterator(); // 得到迭代器，用于遍历list中的所有元素 while (it.hasNext()) {// 如果迭代器中有元素，则返回true System.out.println("\t" + it.next());// 显示该元素 } } @OnClick(R.id.insert) public void onInsertClicked() { long startTime = System.currentTimeMillis(); //获取开始时间 list.add(new User(String.valueOf(System.currentTimeMillis()), "李四")); Collections.sort(list, new PriceComparator()); // 根据时间排序 long endTime = System.currentTimeMillis(); //获取结束时间 Log.i(TAG1, "Insert And Sort程序运行时间： " + (startTime - endTime) + "ms"); System.out.println("按时间排序:"); myprint(list); } // 自定义比较器：按书的价格排序 static class PriceComparator implements Comparator { public int compare(Object object1, Object object2) {// 实现接口中的方法 User p1 = (User) object1; // 强制转换 User p2 = (User) object2; return Integer.valueOf(p1.time).compareTo(Integer.valueOf(p2.time)); } } // 自定义比较器：按书的价格排序 static class TimeComparator implements Comparator { public int compare(Object object1, Object object2) {// 实现接口中的方法 User p1 = (User) object1; // 强制转换 User p2 = (User) object2; return (p1.time).compareTo(p2.time); } } // 自定义比较器：按书的价格排序 static class NameComparator implements Comparator { public int compare(Object object1, Object object2) {// 实现接口中的方法 User p1 = (User) object1; // 强制转换 User p2 = (User) object2; return p1.name.compareTo(p2.name); } } }