目录
1.扑克牌游戏
public class Card {
private String suit;
private int rank;
public Card( int rank,String suit) {
this.suit = suit;
this.rank = rank;
}
@Override
public String toString() {
return"{"+suit+rank+"} ";
}
}
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
public class CardDemo {
public static final String[] stuits={"♠","方块","♥","♣"};
public List<Card> buyCard() {
List<Card> cardList = new ArrayList<>();
for (int i = 0; i < 13; i++) {
for (int j = 0; j < 4; j++) {
int rank = i;
String suit = stuits[j];
Card card = new Card(rank,suit);
cardList.add(card);
}
}
return cardList;
}
public void shuffle(List<Card> cardList){
Random random = new Random();
for (int i =cardList.size()-1; i > 0; i--) {
int index = random.nextInt(i);
swap(cardList,i,index);
}
}
private void swap (List<Card>cardList,int i,int j){
Card tmp = cardList.get(i);
cardList.set(i,cardList.get(j));
cardList.set(j,tmp);
}
public List<List<Card>> play(List<Card>cardList){
List<Card> hand0 = new ArrayList<>();
List<Card> hand1 = new ArrayList<>();
List<Card> hand2 = new ArrayList<>();
List<List<Card>> hand = new ArrayList<>();
hand.add(hand0);
hand.add(hand1);
hand.add(hand2);
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 3; j++) {
Card card = cardList.remove(0);
hand.get(j).add(card);
}
}
return hand;
}
}
import java.util.List;
public class Test {
public static void main(String[] args) {
//买牌
CardDemo cardDemo = new CardDemo();
List<Card> cardList = cardDemo.buyCard();
System.out.println(cardList);
//洗牌
cardDemo.shuffle(cardList);
//轮流发牌
List <List<Card>> ret = cardDemo.play(cardList);
for (int i = 0; i < ret.size(); i++) {
System.out.println("第"+(i+1)+"个人的牌"+ret.get(i));
}
}
}
2.链表基本功能的实现（单项链表）
public class Test {
public static void main(String[] args) {
MySingleList list = new MySingleList();
list.CreatList();
list.clear();
list.display();
}
}
public class MySingleList implements IList {
static class ListNode{
private int val;
private ListNode next;
public ListNode(int val){
this.val = val;
}
}
public ListNode head;
public void CreatList(){
ListNode node1 = new ListNode(12);
ListNode node2 = new ListNode(12);
ListNode node3 = new ListNode(23);
ListNode node4 = new ListNode(45);
ListNode node5 = new ListNode(56);
node1.next = node2;
node2.next = node3;
node3.next = node4;
node4.next = node5;
this.head = node1;
}
@Override
public void addFirst(int data) {
ListNode node = new ListNode(data);
node.next = head;
head = node;
}
@Override
public void addLast(int data) {
ListNode node = new ListNode(data);
ListNode cur = head;
if(head == null){
head = node;
return;
}
while(cur.next != null ){
cur = cur.next;
} cur.next = node;
}
@Override
public void addIndex(int index, int data) {
int len = size();
if(index < 0 || index > len){
System.out.println("index位置不合法");
return;
}
if( index == 0){
addFirst(data);
return;
}if(index == len){
addLast(data);
return;
}
ListNode node = new ListNode(data);
ListNode cur =head;
while(index - 1 != 0){
cur = cur.next;
index--;
}
node.next = cur.next;
cur.next = node;
}
@Override
public boolean contains(int key) {
ListNode cur = head;
while(cur != null){
if(cur.val == key){
return true;
}else
cur = cur.next;
}
return false;
}
@Override
public void remove(int key) {
if(head == null){
return;
}
if(head.val == key){
head = head.next;
return;
}
ListNode cur = findNodeOfKey(key);
if(cur == null){
return;
}
cur.next = cur.next.next;
}
private ListNode findNodeOfKey(int key){
ListNode cur = head;
while(cur.next != null){
if(cur.next.val == key){
return cur;
}
cur = cur.next;
}
return null;
}
@Override
public void removeAllKey(int key) {
if (head == null) {
return;
}
ListNode pre = head;
ListNode cur = head.next;
while (cur != null) {
if (cur.val == key) {
pre.next = cur.next;
cur = cur.next;
} else {
pre = cur;
cur = cur.next;
}
}
if (head.val == key){
head = head.next;
}
}
@Override
public int size() {
ListNode cur = this.head;
int len = 0;
while(cur != null){
len++;
cur = cur.next;
}
System.out.println();
return len;
}
@Override
public void clear() {
ListNode cur = head;
while(cur != null){
ListNode curN = cur.next;
cur.next = null;
cur = curN;
}
head = null;
}
@Override
public void display() {
ListNode cur = head;
while ((cur != null)){
System.out.print(cur.val+" ");
cur = cur.next;
}
}
}
public interface IList {
public void addFirst(int data);
public void addLast(int data);
public void addIndex(int index,int data);
public boolean contains (int key);
public void remove(int key);
public void removeAllKey(int key);
public int size();
public void clear();
public void display();
}
3.移除链表元素力扣
public class Solution {
public ListNode removeElements(ListNode head, int val) {
if(head == null){
return head;
}
ListNode pre = head;
ListNode cur = head.next;
while(cur != null){
if(cur.val == val){
pre.next = cur.next;
cur = cur.next;
}else{
pre = cur;
cur = cur.next;
}
}
if(head.val == val){
head = head.next;
}
return head;
}
}
4.反转链表力扣
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode reverseList(ListNode head) {
if(head == null){
return head;
}
ListNode cur = head.next;
head.next = null;
while(cur != null){
ListNode curN = cur.next;
cur.next = head;
head = cur;
cur = curN;
}
return head;
}
}
5.链表的中间结点
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode middleNode(ListNode head) {
if(head == null){
return head;
}
ListNode fast = head;
ListNode slow = head;
while(fast != null && fast.next != null){
fast = fast.next.next;
slow = slow.next;
}
return slow;
}
}
5.返回倒数第k个节点
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
class Solution {
public int kthToLast(ListNode head, int k) {
if(head == null){
return head.val;
}
ListNode fast = head;
ListNode slow = head;
int count = k - 1;
while(count != 0){
fast = fast.next;
count--;
}
while(fast.next != null){
fast = fast.next;
slow = slow.next;
}
return slow.val;
}
}
6.合并两个有序链表
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
ListNode newHead = new ListNode(-1);
ListNode tmp = newHead;
while(list1 != null && list2 != null){
if(list1.val <= list2.val){
tmp.next = list1;
list1 = list1.next;
tmp = tmp.next;
}else{
tmp.next = list2;
tmp = tmp.next;
list2 = list2.next;
}
}
if(list1 != null){
tmp.next = list1;
}
if(list2 != null){
tmp.next = list2;
}
return newHead.next;
}
}
7.链表基本功能的实现（双向链表）
public class test {
public static MyLinkedList.ListNode mergeTwoLists(MyLinkedList.ListNode list1,MyLinkedList. ListNode list2) {
MyLinkedList. ListNode newHead = new MyLinkedList.ListNode(-1);
MyLinkedList. ListNode tmp = newHead;
while(list1 != null && list2 != null){
if(list1.val < list2.val){
tmp.next = list1;
list1 = list1.next;
tmp = tmp.next;
}
else{
tmp.next = list2;
tmp = tmp.next;
list2 = list2.next;
}
}
if(list1 != null){
tmp.next = list1;
}
if(list2 != null){
tmp.next = list2;
}
return newHead.next;
}
public static void main(String[] args) {
MyLinkedList myLinkedList = new MyLinkedList();
myLinkedList.addLast(1);
myLinkedList.addLast(5);
myLinkedList.addLast(9);
myLinkedList.addLast(21);
myLinkedList.addLast(7);
myLinkedList.addLast(21);
MyLinkedList myLinkedList1 =new MyLinkedList();
myLinkedList1.addLast(1);
myLinkedList1.addLast(5);
myLinkedList1.addLast(9);
myLinkedList1.addLast(21);
myLinkedList1.addLast(7);
myLinkedList1.addLast(21);
MyLinkedList.ListNode newHead = mergeTwoLists( myLinkedList.head,myLinkedList1.head);
myLinkedList.display2(newHead);
}
}
public class MyLinkedList implements IList{
static class ListNode {
public int val;
public ListNode preV;
public ListNode next;
public ListNode(int val) {
this.val = val;
}
}
public ListNode head;
public ListNode last;
@Override
public void addFirst(int data) {
ListNode cur = head;
ListNode node = new ListNode(data);
if(head.next == null){
head = last = node;
}else{
node.next = cur;
cur.preV = node;
head = node;
}
}
@Override
public void addLast(int data) {
ListNode cur = head;
ListNode node = new ListNode(data);
if(head == null) {
head = last = node;
}else{
last.next = node;
node.preV = last;
last = node;
}
}
@Override
//在指点位置增删元素
public void addIndex(int index, int data) {
int len = size();
if(index < 0 || index > len ){
System.out.println("不符合条件");
return;
}if(index == 0){
addFirst(index);
return;
}if(index == len){
addLast(data);
return;
}else{
ListNode cur = findOfKey(index);
ListNode node = new ListNode(data);
node.next = cur;
node.preV = cur.preV;
cur.preV.next = node;
cur.preV = node;
}
}
private ListNode findOfKey(int index){
ListNode cur = head;
while(index != 0){
cur = cur.next;
index--;
}
return cur;
}
@Override
public boolean contains(int key) {
ListNode cur = head;
while(cur != null){
if(cur.val == key)
{
return true;
}
cur = cur.next;
}
return false;
}
@Override
public void remove(int key) {
ListNode cur = head;
while(cur != null) {
if (cur.val == key) {
if (cur == head) {
head = head.next;
if (head != null) {
head.preV = null;
}
} else {
cur.preV.next = cur.next;
if ( cur.next == null) {
last = last.preV;
}else {
cur.next.preV = cur.preV;
}
}
}
cur =cur.next;
}
}
@Override
public void removeAllKey(int key) {
ListNode cur = head;
while(cur != null) {
if (cur.val == key) {
if (cur == head) {
head = head.next;
if (head != null) {
head.preV = null;
}
}
else {
cur.preV.next = cur.next;
if (cur.next == null) {
last = last.preV;
}
cur.next.preV = cur.preV;
}
}
cur = cur.next;
}
}
@Override
public int size() {
ListNode cur = head;
int len = 0;
while(cur != null){
len++;
cur = cur.next;
}
return len;
}
@Override
public void clear() {
ListNode cur = head;
if(cur != null){
ListNode curN = cur.next;
cur.preV = null;
cur.next = null;
cur = curN;
}
head = null;
last = null;
}
@Override
public void display() {
ListNode cur = head;
while(cur != null){
System.out.print(cur.val+" ");
cur = cur.next;
}
System.out.println();
}
//在指定位置进行打印
public void display2(ListNode newHead) {
ListNode cur = head;
while (cur != null) {
System.out.print(cur.val + " ");
cur = cur.next;
}
System.out.println();
}
public ListNode reverseList() {
if(head == null){
return head;
}
ListNode cur = head.next;
head.next = null;
while(cur != null){
ListNode curN = cur.next;
cur.next = head;
head = cur;
cur = curN;
}
return head;
}
}
public interface IList {
public void addFirst(int data);
public void addLast(int data);
public void addIndex(int index,int data);
public boolean contains (int key);
public void remove(int key);
public void removeAllKey(int key);
public int size();
public void clear();
public void display();
}
8.链表分割
import java.util.*;
/*
public class ListNode {
int val;
ListNode next = null;
ListNode(int val) {
this.val = val;
}
}*/
public class Partition {
public ListNode partition(ListNode pHead, int x) {
ListNode as = null;
ListNode ae = null;
ListNode bs = null;
ListNode be = null;
ListNode cur = pHead;
while(cur != null){
if(cur.val < x){
if(as == null){
as = ae = cur;
}else{
ae.next = cur;
ae = ae.next;
}
}else{
if(bs == null){
bs = be =cur;
}else{
be.next = cur;
be = be.next;
}
}
cur = cur.next;
}
if(as == null){
return bs;
}
ae.next = bs;
if(bs != null){
be.next = null;
}
return as;
}
}