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Add queue array impl in C (#300)
* feat(codes/c): Add array_queue.c initialization * feat(codes/c): Add array_queue.c impl * style(codes/c): Update array_queue.c code style * style(codes/c): Update array_queue.c code style
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2 changed files with 132 additions and 1 deletions
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add_executable(array_stack array_stack.c)
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add_executable(linkedlist_stack linkedlist_stack.c)
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add_executable(linkedlist_stack linkedlist_stack.c)
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add_executable(array_queue array_queue.c)
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130
codes/c/chapter_stack_and_queue/array_queue.c
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130
codes/c/chapter_stack_and_queue/array_queue.c
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/**
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* File: array_queue.c
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* Created Time: 2023-01-28
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* Author: Zero (glj0@outlook.com)
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*/
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#include "../include/include.h"
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/* 基于环形数组形成的队列 */
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struct ArrayQueue {
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int *nums; // 用于存储队列元素的数组
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int cap; // 队列容量
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int front; // 头指针,指向队首
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int rear; // 尾指针,指向队尾 + 1
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};
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typedef struct ArrayQueue ArrayQueue;
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/* 构造函数 */
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ArrayQueue *newArrayQueue(int capacity) {
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ArrayQueue *queue = (ArrayQueue *) malloc(sizeof(ArrayQueue));
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// 初始化数组
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queue->cap = capacity;
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queue->nums = (int *) malloc(sizeof(int) * queue->cap);
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queue->front = 0;
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queue->rear = 0;
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return queue;
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}
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/* 析构函数 */
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void delArrayQueue(ArrayQueue *queue) {
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free(queue->nums);
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queue->cap = 0;
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}
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/* 获取队列的容量 */
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int capacity(ArrayQueue *queue) {
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return queue->cap;
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}
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/* 获取队列的长度 */
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int size(ArrayQueue *queue) {
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// 由于将数组看作环形队列,可能 rear < front,因此需要取余数
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return (capacity(queue) + queue->rear - queue->front) % capacity(queue);
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}
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/* 判断队列是否为空 */
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bool empty(ArrayQueue *queue) {
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return queue->rear - queue->front == 0;
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}
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/* 访问队首元素 */
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int peek(ArrayQueue *queue) {
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assert(size(queue) != 0);
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return queue->nums[queue->front];
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}
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/* 入队 */
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void offer(ArrayQueue *queue, int num) {
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if (size(queue) == capacity(queue)) {
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printf("队列已满\r\n");
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return;
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}
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queue->nums[queue->rear] = num;
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queue->rear = (queue->rear + 1) % capacity(queue);
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}
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/* 出队 */
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void poll(ArrayQueue *queue) {
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int num = peek(queue);
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queue->front = (queue->front + 1) % capacity(queue);
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}
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/* 打印基于环形数组形成的队列 */
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void printArrayQueue(ArrayQueue *queue) {
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int siz = size(queue);
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int cap = capacity(queue);
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int arr[siz];
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// 拷贝
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for (int i = 0, j = queue->front; i < siz; i++, j++) {
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arr[i] = queue->nums[j % cap];
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}
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printArray(arr, siz);
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}
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/* Driver Code */
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int main() {
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/* 初始化队列 */
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int capacity = 10;
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ArrayQueue *queue = newArrayQueue(capacity);
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/* 元素入队 */
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offer(queue, 1);
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offer(queue, 3);
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offer(queue, 2);
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offer(queue, 5);
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offer(queue, 4);
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printf("队列 queue = ");
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printArrayQueue(queue);
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/* 访问队首元素 */
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int peekNum = peek(queue);
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printf("队首元素 peek = %d\r\n", peekNum);
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/* 元素出队 */
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poll(queue);
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printf("出队元素 poll = %d,出队后 queue = ", peekNum);
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printArrayQueue(queue);
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/* 获取队列的长度 */
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int queueSize = size(queue);
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printf("队列长度 size = %d\r\n", queueSize);
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/* 判断队列是否为空 */
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bool isEmpty = empty(queue);
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printf("队列是否为空 = %s\r\n", isEmpty ? "true" : "false");
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/* 测试环形数组 */
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for (int i = 0; i < 10; i++) {
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offer(queue, i);
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poll(queue);
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printf("第 %d 轮入队 + 出队后 queue = ", i);
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printArrayQueue(queue);
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}
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// 释放内存
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delArrayQueue(queue);
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return 0;
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}
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