Java 如何计算ArrayList中的重复项<;整数>;并将它们作为字符串返回
如何计算ArrayList中的重复项并将其作为字符串返回 例如,我有ArrayList[1,3,4,4,5,6,3,4,6],我想有一个方法来计算数组项的出现次数,并在它们以如下输出格式多次出现时显示它们: 3-2;4 - 3; 6 - 2; 我试过这样的东西 `Java 如何计算ArrayList中的重复项<;整数>;并将它们作为字符串返回,java,arraylist,duplicates,counter,Java,Arraylist,Duplicates,Counter,如何计算ArrayList中的重复项并将其作为字符串返回 例如,我有ArrayList[1,3,4,4,5,6,3,4,6],我想有一个方法来计算数组项的出现次数,并在它们以如下输出格式多次出现时显示它们: 3-2;4 - 3; 6 - 2; 我试过这样的东西 ` import java.util.ArrayList; 导入java.util.Random; 导入java.util.HashSet; 导入java.util.Set; 导入java.util.Collections; 公共类生成器
import java.util.ArrayList;
导入java.util.Random;
导入java.util.HashSet;
导入java.util.Set;
导入java.util.Collections;
公共类生成器{
公共国际ileKostek;
Random rand=新的Random();
字符串wynik;
私人ArrayList rzuty;
私人ArrayList dublety;
私有int rzut=0;
伊莱西安私人酒店;
内苏马私人酒店;
公共发电公司{
rzuty=newarraylist();
}
公共发电公司(国际伊莱科斯特克、国际伊莱希安){
ileKostek=ileKostek;
ileScian=ileScian;
rzuty=newarraylist();
}
公共空间Rzucaj(国际IleKostek、国际IleScian){
ileKostek=ileKostek;
ileScian=ileScian;
对于(int i=0;i1){
添加(i+“-”+wystapienia+“;”);
}
}
for(int i=0;i
`
我只是从编程开始我的冒险
我在另一节课上说
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.Random;
public class MainActivity extends ActionBarActivity {
GeneratorKostek Kostki = new GeneratorKostek();
ArrayList<Integer> wyniki = new ArrayList<Integer>();
String wynik;
Button btnk6, btn2k6, btn3k6, btn4k6, btn5k6, btn6k6;
TextView tvWynik;
EditText etInfo;
Random rand = new Random();
int kostka1, kostka2, kostka3, kostka4, kostka5, kostka6;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnk6 = (Button) findViewById(R.id.btnk6);
btn2k6 = (Button) findViewById(R.id.btn2k6);
btn3k6 = (Button) findViewById(R.id.btn3k6);
btn4k6 = (Button) findViewById(R.id.btn4k6);
btn5k6 = (Button) findViewById(R.id.btn5k6);
btn6k6 = (Button) findViewById(R.id.btn6k6);
tvWynik = (TextView) findViewById(R.id.tvWynik);
etInfo = (EditText) findViewById(R.id.etInfo);
btnk6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(1, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn2k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(2, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn3k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(3, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn4k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(4, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn5k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(5, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn6k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(6, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
etInfo.setText(Kostki.PrezentacjaDubletow());
}
});
// if (savedInstanceState == null) {
// getSupportFragmentManager().beginTransaction()
// .add(R.id.container, new PlaceholderFragment())
// .commit();
// }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
switch (item.getItemId()) {
case R.id.action_settings:
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}`
导入android.os.Bundle;
导入android.support.v4.app.Fragment;
导入android.support.v7.app.ActionBarActivity;
导入android.view.LayoutInflater;
导入android.view.Menu;
导入android.view.MenuItem;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.Button;
导入android.widget.EditText;
导入android.widget.TextView;
导入java.util.ArrayList;
导入java.util.Random;
公共类MainActivity扩展了ActionBarActivity{
GeneratorKostek Kostki=新GeneratorKostek();
ArrayList wyniki=新的ArrayList();
字符串wynik;
按钮btnk6、btn2k6、btn3k6、btn4k6、btn5k6、btn6k6;
TextView-tvWynik;
编辑文本信息;
Random rand=新的Random();
国际科斯特卡1号、科斯特卡2号、科斯特卡3号、科斯特卡4号、科斯特卡5号、科斯特卡6号;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnk6=(按钮)findViewById(R.id.btnk6);
btn2k6=(按钮)findViewById(R.id.btn2k6);
btn3k6=(按钮)findViewById(R.id.btn3k6);
btn4k6=(按钮)findViewById(R.id.btn4k6);
btn5k6=(按钮)findViewById(R.id.btn5k6);
btn6k6=(按钮)findViewById(R.id.btn6k6);
tvWynik=(TextView)findViewById(R.id.tvWynik);
etInfo=(EditText)findViewById(R.id.etInfo);
btnk6.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
Kostki.CzyscRzuty();
Kostki.Rzucaj(1,6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn2k6.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
Kostki.CzyscRzuty();
Kostki.Rzucaj(2,6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn3k6.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
Kostki.CzyscRzuty();
Kostki.Rzucaj(3,6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn4k6.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
Kostki.CzyscRzuty();
Kostki.Rzucaj(4,6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn5k6.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
Kostki.CzyscRzuty();
Kostki.Rzucaj(5,6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn6k6.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
Kostki.CzyscRzuty();
Kostki.Rzucaj(6,6);
tvWynik.setText(Kostki.PrezentujRzuty());
etInfo.setText(Kostki.PrezentacjaDubletow());
}
});
//如果(savedInstanceState==null){
//getSupportFragmentManager().beginTransaction()
//.add(R.id.container,新的占位符片段())
//.commit();
// }
}
@凌驾
公共布尔onCreateOptions菜单(菜单){
//为菜单充气;这会将项目添加到操作栏(如果存在)。
getMenuInflater().充气(R.menu.main,menu);
返回true;
}
@凌驾
公共布尔值onOptionsItemSelected(菜单项项){
//处理操作栏项目单击此处。操作栏将
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.Random;
public class MainActivity extends ActionBarActivity {
GeneratorKostek Kostki = new GeneratorKostek();
ArrayList<Integer> wyniki = new ArrayList<Integer>();
String wynik;
Button btnk6, btn2k6, btn3k6, btn4k6, btn5k6, btn6k6;
TextView tvWynik;
EditText etInfo;
Random rand = new Random();
int kostka1, kostka2, kostka3, kostka4, kostka5, kostka6;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnk6 = (Button) findViewById(R.id.btnk6);
btn2k6 = (Button) findViewById(R.id.btn2k6);
btn3k6 = (Button) findViewById(R.id.btn3k6);
btn4k6 = (Button) findViewById(R.id.btn4k6);
btn5k6 = (Button) findViewById(R.id.btn5k6);
btn6k6 = (Button) findViewById(R.id.btn6k6);
tvWynik = (TextView) findViewById(R.id.tvWynik);
etInfo = (EditText) findViewById(R.id.etInfo);
btnk6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(1, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn2k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(2, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn3k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(3, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn4k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(4, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn5k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(5, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
}
});
btn6k6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Kostki.CzyscRzuty();
Kostki.Rzucaj(6, 6);
tvWynik.setText(Kostki.PrezentujRzuty());
etInfo.setText(Kostki.PrezentacjaDubletow());
}
});
// if (savedInstanceState == null) {
// getSupportFragmentManager().beginTransaction()
// .add(R.id.container, new PlaceholderFragment())
// .commit();
// }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
switch (item.getItemId()) {
case R.id.action_settings:
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}`
package com.count.list.items;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class ListItemCounter
{
public void start()
{
List<Integer> list = getList(1, 1, 5, 3, 7, 3, 11, 2, 3, 1);
Map<Integer, Integer> map = new HashMap<Integer, Integer>();
for (Integer i : list)
{
Integer retrievedValue = map.get(i);
if (null == retrievedValue)
{
map.put(i, 1);
}
else
{
map.put(i, retrievedValue + 1);
}
}
System.out.println("list: " + list);
printCount(map);
}
private List<Integer> getList(int... numbers)
{
List<Integer> list = new ArrayList<Integer>();
for (int i : numbers)
{
list.add(i);
}
return list;
}
private void printCount(Map<Integer, Integer> map)
{
for (Integer key : map.keySet())
{
System.out.println("number: " + key + ", count: " + map.get(key));
}
}
}
String input = "I am am akash pal pal pal";
System.out.println("Before removing duplicate: "+input);
String[] arr = input.split(" ");
int count=0;
System.out.println(arr.length);
for (int i = 0; i < arr.length; i++) {
if (arr[i] != null) {
for (int j = i + 1; j < arr.length; j++) {
if (arr[i].equalsIgnoreCase(arr[j])) {
//System.out.println("Duplicates are \n"+arr[i]);
arr[j] = null;count++;
}
}
}
}
System.out.println("After");
for (int k = 0; k < arr.length; k++) {
if (arr[k] != null)
System.out.print(arr[k] + " ");
}
System.out.println("");
System.out.println("Duplicates \t"+count);