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

codes/cpp/chapter_stack_and_queue/array_deque.cpp

@@ -0,0 +1,157 @@
+/**
+ * File: array_deque->cpp
+ * Created Time: 2023-03-02
+ * Author: Krahets ([email protected])
+ */
+
+#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;
+}

codes/cpp/chapter_stack_and_queue/linkedlist_deque.cpp

@@ -0,0 +1,188 @@
+/**
+ * File: linkedlist_deque->cpp
+ * Created Time: 2023-03-02
+ * Author: Krahets ([email protected])
+ */
+
+#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;
+}

codes/go/chapter_stack_and_queue/linkedlist_deque.go

@@ -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
 }
 

codes/java/chapter_stack_and_queue/linkedlist_deque.java

@@ -22,15 +22,15 @@ 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;
     }
 
     /* 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 @@ else if (isFront) {
             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 @@ private Integer poll(boolean isFront) {
             }
             rear = rPrev;    // 更新尾结点
         }
-        size--; // 更新队列长度
+        queSize--; // 更新队列长度
         return val;
     }