Add C++ code for the linkedlist deque and array deque (#400)

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Yudong Jin 2023-03-02 03:00:14 +08:00 committed by GitHub
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4 changed files with 351 additions and 6 deletions

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@ -0,0 +1,157 @@
/**
* File: array_deque->cpp
* Created Time: 2023-03-02
* Author: Krahets (krahets@163.com)
*/
#include "../include/include.hpp"
/* 基于环形数组实现的双向队列 */
class ArrayDeque {
private:
vector<int> nums; // 用于存储双向队列元素的数组
int front; // 队首指针,指向队首元素
int queSize; // 双向队列长度
public:
/* 构造方法 */
ArrayDeque(int capacity) {
nums.resize(capacity);
front = queSize = 0;
}
/* 获取双向队列的容量 */
int capacity() {
return nums.size();
}
/* 获取双向队列的长度 */
int size() {
return queSize;
}
/* 判断双向队列是否为空 */
bool isEmpty() {
return queSize == 0;
}
/* 计算环形数组索引 */
int index(int i) {
// 通过取余操作实现数组首尾相连
// 当 i 越过数组尾部后,回到头部
// 当 i 越过数组头部后,回到尾部
return (i + capacity()) % capacity();
}
/* 队首入队 */
void pushFirst(int num) {
if (queSize == capacity()) {
cout << "双向队列已满" << endl;
return;
}
// 队首指针向左移动一位
// 通过取余操作,实现 front 越过数组头部后回到尾部
front = index(front - 1);
// 将 num 添加至队首
nums[front] = num;
queSize++;
}
/* 队尾入队 */
void pushLast(int num) {
if (queSize == capacity()) {
cout << "双向队列已满" << endl;
return;
}
// 计算尾指针,指向队尾索引 + 1
int rear = index(front + queSize);
// 将 num 添加至队尾
nums[rear] = num;
queSize++;
}
/* 队首出队 */
int pollFirst() {
int num = peekFirst();
// 队首指针向后移动一位
front = index(front + 1);
queSize--;
return num;
}
/* 队尾出队 */
int pollLast() {
int num = peekLast();
queSize--;
return num;
}
/* 访问队首元素 */
int peekFirst() {
if (isEmpty())
throw out_of_range("双向队列为空");
return nums[front];
}
/* 访问队尾元素 */
int peekLast() {
if (isEmpty())
throw out_of_range("双向队列为空");
// 计算尾元素索引
int last = index(front + queSize - 1);
return nums[last];
}
/* 返回数组用于打印 */
vector<int> toVector() {
// 仅转换有效长度范围内的列表元素
vector<int> res(queSize);
for (int i = 0, j = front; i < queSize; i++, j++) {
res[i] = nums[index(j)];
}
return res;
}
};
/* Driver Code */
int main() {
/* 初始化双向队列 */
ArrayDeque *deque = new ArrayDeque(10);
deque->pushLast(3);
deque->pushLast(2);
deque->pushLast(5);
cout << "双向队列 deque = ";
PrintUtil::printVector(deque->toVector());
/* 访问元素 */
int peekFirst = deque->peekFirst();
cout << "队首元素 peekFirst = " << peekFirst << endl;
int peekLast = deque->peekLast();
cout << "队尾元素 peekLast = " << peekLast << endl;
/* 元素入队 */
deque->pushLast(4);
cout << "元素 4 队尾入队后 deque = ";
PrintUtil::printVector(deque->toVector());
deque->pushFirst(1);
cout << "元素 1 队首入队后 deque = ";
PrintUtil::printVector(deque->toVector());
/* 元素出队 */
int pollLast = deque->pollLast();
cout << "队尾出队元素 = " << pollLast << ",队尾出队后 deque = ";
PrintUtil::printVector(deque->toVector());
int pollFirst = deque->pollFirst();
cout << "队首出队元素 = " << pollFirst << ",队首出队后 deque = ";
PrintUtil::printVector(deque->toVector());
/* 获取双向队列的长度 */
int size = deque->size();
cout << "双向队列长度 size = " << size << endl;
/* 判断双向队列是否为空 */
bool isEmpty = deque->isEmpty();
cout << "双向队列是否为空 = " << boolalpha << isEmpty << endl;
return 0;
}

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@ -0,0 +1,188 @@
/**
* File: linkedlist_deque->cpp
* Created Time: 2023-03-02
* Author: Krahets (krahets@163.com)
*/
#include "../include/include.hpp"
/* 双向链表结点 */
struct DoubleListNode {
int val; // 结点值
DoubleListNode *next; // 后继结点指针
DoubleListNode *prev; // 前驱结点指针
DoubleListNode(int val) : val(val), prev(nullptr), next(nullptr) {}
};
/* 基于双向链表实现的双向队列 */
class LinkedListDeque {
private:
DoubleListNode *front, *rear; // 头结点 front ,尾结点 rear
int queSize = 0; // 双向队列的长度
public:
/* 构造方法 */
LinkedListDeque() : front(nullptr), rear(nullptr) {}
/* 析构方法 */
~LinkedListDeque() {
// 释放内存
DoubleListNode *pre, *cur = front;
while (cur != nullptr) {
pre = cur;
cur = cur->next;
delete pre;
}
}
/* 获取双向队列的长度 */
int size() {
return queSize;
}
/* 判断双向队列是否为空 */
bool isEmpty() {
return size() == 0;
}
/* 入队操作 */
void push(int num, bool isFront) {
DoubleListNode *node = new DoubleListNode(num);
// 若链表为空,则令 front, rear 都指向 node
if (isEmpty())
front = rear = node;
// 队首入队操作
else if (isFront) {
// 将 node 添加至链表头部
front->prev = node;
node->next = front;
front = node; // 更新头结点
// 队尾入队操作
} else {
// 将 node 添加至链表尾部
rear->next = node;
node->prev = rear;
rear = node; // 更新尾结点
}
queSize++; // 更新队列长度
}
/* 队首入队 */
void pushFirst(int num) {
push(num, true);
}
/* 队尾入队 */
void pushLast(int num) {
push(num, false);
}
/* 出队操作 */
int poll(bool isFront) {
// 若队列为空,直接返回 -1
if (isEmpty())
return -1;
int val;
// 队首出队操作
if (isFront) {
val = front->val; // 暂存头结点值
// 删除头结点
DoubleListNode *fNext = front->next;
if (fNext != nullptr) {
fNext->prev = nullptr;
front->next = nullptr;
}
front = fNext; // 更新头结点
// 队尾出队操作
} else {
val = rear->val; // 暂存尾结点值
// 删除尾结点
DoubleListNode *rPrev = rear->prev;
if (rPrev != nullptr) {
rPrev->next = nullptr;
rear->prev = nullptr;
}
rear = rPrev; // 更新尾结点
}
queSize--; // 更新队列长度
return val;
}
/* 队首出队 */
int pollFirst() {
return poll(true);
}
/* 队尾出队 */
int pollLast() {
return poll(false);
}
/* 访问队首元素 */
int peekFirst() {
return isEmpty() ? -1 : front->val;
}
/* 访问队尾元素 */
int peekLast() {
return isEmpty() ? -1 : rear->val;
}
/* 返回数组用于打印 */
vector<int> toVector() {
DoubleListNode *node = front;
vector<int> res(size());
for (int i = 0; i < res.size(); i++) {
res[i] = node->val;
node = node->next;
}
return res;
}
};
/* Driver Code */
int main() {
/* 初始化双向队列 */
LinkedListDeque *deque = new LinkedListDeque();
deque->pushLast(3);
deque->pushLast(2);
deque->pushLast(5);
cout << "双向队列 deque = ";
PrintUtil::printVector(deque->toVector());
/* 访问元素 */
int peekFirst = deque->peekFirst();
cout << "队首元素 peekFirst = " << peekFirst << endl;
int peekLast = deque->peekLast();
cout << "队尾元素 peekLast = " << peekLast << endl;
/* 元素入队 */
deque->pushLast(4);
cout << "元素 4 队尾入队后 deque =" ;
PrintUtil::printVector(deque->toVector());
deque->pushFirst(1);
cout << "元素 1 队首入队后 deque = ";
PrintUtil::printVector(deque->toVector());
/* 元素出队 */
int pollLast = deque->pollLast();
cout << "队尾出队元素 = " << pollLast << ",队尾出队后 deque = ";
PrintUtil::printVector(deque->toVector());
int pollFirst = deque->pollFirst();
cout << "队首出队元素 = " << pollFirst << ",队首出队后 deque = ";
PrintUtil::printVector(deque->toVector());
/* 获取双向队列的长度 */
int size = deque->size();
cout << "双向队列长度 size = " << size << endl;
/* 判断双向队列是否为空 */
bool isEmpty = deque->isEmpty();
cout << "双向队列是否为空 = " << boolalpha << isEmpty << endl;
// 释放内存
delete deque;
return 0;
}

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@ -8,9 +8,9 @@ import (
"container/list"
)
/* 基于链表实现的双端队列 */
/* 基于双向链表实现的双向队列 */
type linkedListDeque struct {
// 使用内置包 list 来实现栈
// 使用内置包 list
data *list.List
}

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@ -22,7 +22,7 @@ class ListNode {
/* 基于双向链表实现的双向队列 */
class LinkedListDeque {
private ListNode front, rear; // 头结点 front 尾结点 rear
private int size = 0; // 双向队列的长度
private int queSize = 0; // 双向队列的长度
public LinkedListDeque() {
front = rear = null;
@ -30,7 +30,7 @@ class LinkedListDeque {
/* 获取双向队列的长度 */
public int size() {
return size;
return queSize;
}
/* 判断双向队列是否为空 */
@ -57,7 +57,7 @@ class LinkedListDeque {
node.prev = rear;
rear = node; // 更新尾结点
}
size++; // 更新队列长度
queSize++; // 更新队列长度
}
/* 队首入队 */
@ -97,7 +97,7 @@ class LinkedListDeque {
}
rear = rPrev; // 更新尾结点
}
size--; // 更新队列长度
queSize--; // 更新队列长度
return val;
}