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chapter_stack_and_queue/deque.md
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@ -452,19 +452,122 @@ comments: true
=== "C++" === "C++"
```cpp title="linkedlist_deque.cpp" ```cpp title="linkedlist_deque.cpp"
[class]{ListNode}-[func]{}
[class]{LinkedListDeque}-[func]{}
``` ```
=== "Python" === "Python"
```python title="linkedlist_deque.py" ```python title="linkedlist_deque.py"
""" 双向链表结点 """
class ListNode:
def __init__(self, val):
self.val = val
self.next = None # 后继结点引用（指针）
self.prev = None # 前驱结点引用（指针）
""" 基于双向链表实现的双向队列 """
class LinkedListDeque:
""" 构造方法 """
def __init__(self):
self.front, self.rear = None, None # 头结点 front ，尾结点 rear
self.__size = 0 # 双向队列的长度
""" 获取双向队列的长度 """
def size(self):
return self.__size
""" 判断双向队列是否为空 """
def is_empty(self):
return self.size() == 0
""" 入队操作 """
def push(self, num, is_front):
node = ListNode(num)
# 若链表为空，则令 front, rear 都指向 node
if self.is_empty():
self.front = self.rear = node
# 队首入队操作
elif is_front:
# 将 node 添加至链表头部
self.front.prev = node
node.next = self.front
self.front = node # 更新头结点
# 队尾入队操作
else:
# 将 node 添加至链表尾部
self.rear.next = node
node.prev = self.rear
self.rear = node # 更新尾结点
self.__size += 1 # 更新队列长度
""" 队首入队 """
def push_first(self, num):
self.push(num, True)
""" 队尾入队 """
def push_last(self, num):
self.push(num, False)
""" 出队操作 """
def poll(self, is_front):
# 若队列为空，直接返回 None
if self.is_empty():
return None
# 队首出队操作
if is_front:
val = self.front.val # 暂存头结点值
# 删除头结点
fnext = self.front.next
if fnext != None:
fnext.prev = None
self.front.next = None
self.front = fnext # 更新头结点
# 队尾出队操作
else:
val = self.rear.val # 暂存尾结点值
# 删除尾结点
rprev = self.rear.prev
if rprev != None:
rprev.next = None
self.rear.prev = None
self.rear = rprev # 更新尾结点
self.__size -= 1 # 更新队列长度
return val
""" 队首出队 """
def poll_first(self):
return self.poll(True)
""" 队尾出队 """
def poll_last(self):
return self.poll(False)
""" 访问队首元素 """
def peek_first(self):
return None if self.is_empty() else self.front.val
""" 访问队尾元素 """
def peek_last(self):
return None if self.is_empty() else self.rear.val
""" 返回数组用于打印 """
def to_array(self):
node = self.front
res = [0] * self.size()
for i in range(self.size()):
res[i] = node.val
node = node.next
return res
``` ```
=== "Go" === "Go"
```go title="linkedlist_deque.go" ```go title="linkedlist_deque.go"
[class]{ListNode}-[func]{}
[class]{LinkedListDeque}-[func]{}
``` ```
=== "JavaScript" === "JavaScript"
@ -724,7 +827,9 @@ comments: true
=== "C" === "C"
```c title="linkedlist_deque.c" ```c title="linkedlist_deque.c"
[class]{ListNode}-[func]{}
[class]{LinkedListDeque}-[func]{}
``` ```
=== "C#" === "C#"
@ -872,7 +977,174 @@ comments: true
=== "Zig" === "Zig"
```zig title="linkedlist_deque.zig" ```zig title="linkedlist_deque.zig"
// 双向链表结点
fn ListNode(comptime T: type) type {
return struct {
const Self = @This();
val: T = undefined, // 结点值
next: ?*Self = null, // 后继结点引用（指针）
prev: ?*Self = null, // 前驱结点引用（指针）
// Initialize a list node with specific value
pub fn init(self: *Self, x: i32) void {
self.val = x;
self.next = null;
self.prev = null;
}
};
}
// 基于双向链表实现的双向队列
fn LinkedListDeque(comptime T: type) type {
return struct {
const Self = @This();
front: ?*ListNode(T) = null, // 头结点 front
rear: ?*ListNode(T) = null, // 尾结点 rear
deqSize: usize = 0, // 双向队列的长度
mem_arena: ?std.heap.ArenaAllocator = null,
mem_allocator: std.mem.Allocator = undefined, // 内存分配器
// 构造方法（分配内存+初始化队列）
pub fn init(self: *Self, allocator: std.mem.Allocator) !void {
if (self.mem_arena == null) {
self.mem_arena = std.heap.ArenaAllocator.init(allocator);
self.mem_allocator = self.mem_arena.?.allocator();
}
self.front = null;
self.rear = null;
self.deqSize = 0;
}
// 析构方法（释放内存）
pub fn deinit(self: *Self) void {
if (self.mem_arena == null) return;
self.mem_arena.?.deinit();
}
// 获取双向队列的长度
pub fn size(self: *Self) usize {
return self.deqSize;
}
// 判断双向队列是否为空
pub fn isEmpty(self: *Self) bool {
return self.size() == 0;
}
// 入队操作
pub fn push(self: *Self, num: T, isFront: bool) !void {
var node = try self.mem_allocator.create(ListNode(T));
node.init(num);
// 若链表为空，则令 front, rear 都指向 node
if (self.isEmpty()) {
self.front = node;
self.rear = node;
// 队首入队操作
} else if (isFront) {
// 将 node 添加至链表头部
self.front.?.prev = node;
node.next = self.front;
self.front = node; // 更新头结点
// 队尾入队操作
} else {
// 将 node 添加至链表尾部
self.rear.?.next = node;
node.prev = self.rear;
self.rear = node; // 更新尾结点
}
self.deqSize += 1; // 更新队列长度
}
// 队首入队
pub fn pushFirst(self: *Self, num: T) !void {
try self.push(num, true);
}
// 队尾入队
pub fn pushLast(self: *Self, num: T) !void {
try self.push(num, false);
}
// 出队操作
pub fn poll(self: *Self, isFront: bool) T {
if (self.isEmpty()) @panic("双向队列为空");
var val: T = undefined;
// 队首出队操作
if (isFront) {
val = self.front.?.val; // 暂存头结点值
// 删除头结点
var fNext = self.front.?.next;
if (fNext != null) {
fNext.?.prev = null;
self.front.?.next = null;
}
self.front = fNext; // 更新头结点
// 队尾出队操作
} else {
val = self.rear.?.val; // 暂存尾结点值
// 删除尾结点
var rPrev = self.rear.?.prev;
if (rPrev != null) {
rPrev.?.next = null;
self.rear.?.prev = null;
}
self.rear = rPrev; // 更新尾结点
}
self.deqSize -= 1; // 更新队列长度
return val;
}
// 队首出队
pub fn pollFirst(self: *Self) T {
return self.poll(true);
}
// 队尾出队
pub fn pollLast(self: *Self) T {
return self.poll(false);
}
// 访问队首元素
pub fn peekFirst(self: *Self) T {
if (self.isEmpty()) @panic("双向队列为空");
return self.front.?.val;
}
// 访问队尾元素
pub fn peekLast(self: *Self) T {
if (self.isEmpty()) @panic("双向队列为空");
return self.rear.?.val;
}
// 将链表转换为数组
pub fn toArray(self: *Self) ![]T {
var node = self.front;
var res = try self.mem_allocator.alloc(T, self.size());
std.mem.set(T, res, @as(T, 0));
var i: usize = 0;
while (i < res.len) : (i += 1) {
res[i] = node.?.val;
node = node.?.next;
}
return res;
}
// 打印双向队列
pub fn print(self: *Self) !void {
var nums = try self.toArray();
std.debug.print("[", .{});
if (nums.len > 0) {
for (nums) |num, j| {
std.debug.print("{}{s}", .{num, if (j == nums.len - 1) "]" else " <-> " });
}
} else {
std.debug.print("]", .{});
}
}
};
}
``` ```
### 基于数组的实现 ### 基于数组的实现
@ -1008,43 +1280,125 @@ comments: true
=== "C++" === "C++"
```cpp title="array_deque.cpp" ```cpp title="array_deque.cpp"
[class]{ArrayDeque}-[func]{}
``` ```
=== "Python" === "Python"
```python title="array_deque.py" ```python title="array_deque.py"
""" 基于环形数组实现的双向队列 """
class ArrayDeque:
""" 构造方法 """
def __init__(self, capacity):
self.nums = [0] * capacity
self.front = 0
self.que_size = 0
""" 获取双向队列的容量 """
def capacity(self):
return len(self.nums)
""" 获取双向队列的长度 """
def size(self):
return self.que_size
""" 判断双向队列是否为空 """
def is_empty(self):
return self.que_size == 0
""" 计算环形数组索引 """
def index(self, 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 + self.capacity()) % self.capacity()
""" 队首入队 """
def push_first(self, num):
if self.que_size == self.capacity():
print("双向队列已满")
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
self.front = self.index(self.front-1)
# 将 num 添加至队首
self.nums[self.front] = num
self.que_size += 1
""" 队尾入队 """
def push_last(self, num):
if self.que_size == self.capacity():
print("双向队列已满")
return
# 计算尾指针，指向队尾索引 + 1
rear = self.index(self.front + self.que_size)
# 将 num 添加至队尾
self.nums[rear] = num
self.que_size += 1
""" 队首出队 """
def poll_first(self):
num = self.peek_first()
# 队首指针向后移动一位
self.front = self.index(self.front+1)
self.que_size -= 1
return num
""" 队尾出队 """
def poll_last(self):
num = self.peek_last()
self.que_size -= 1
return num
""" 访问队首元素 """
def peek_first(self):
assert not self.is_empty(), "双向队列为空"
return self.nums[self.front]
""" 访问队尾元素 """
def peek_last(self):
assert not self.is_empty(), "双向队列为空"
# 计算尾元素索引
last = self.index(self.front + self.que_size - 1)
return self.nums[last]
""" 返回数组用于打印 """
def to_array(self):
# 仅转换有效长度范围内的列表元素
res = []
for i in range(self.que_size):
res.append(self.nums[self.index(self.front+i)])
return res
``` ```
=== "Go" === "Go"
```go title="array_deque.go" ```go title="array_deque.go"
[class]{ArrayDeque}-[func]{}
``` ```
=== "JavaScript" === "JavaScript"
```js title="array_deque.js" ```js title="array_deque.js"
[class]{ArrayDeque}-[func]{}
``` ```
=== "TypeScript" === "TypeScript"
```typescript title="array_deque.ts" ```typescript title="array_deque.ts"
[class]{ArrayDeque}-[func]{}
``` ```
=== "C" === "C"
```c title="array_deque.c" ```c title="array_deque.c"
[class]{ArrayDeque}-[func]{}
``` ```
=== "C#" === "C#"
```csharp title="array_deque.cs" ```csharp title="array_deque.cs"
[class]{ArrayDeque}-[func]{}
``` ```
=== "Swift" === "Swift"
@ -1162,5 +1516,5 @@ comments: true
=== "Zig" === "Zig"
```zig title="array_deque.zig" ```zig title="array_deque.zig"
[class]{ArrayDeque}-[func]{}
``` ```