122 lines
3.1 KiB
C
122 lines
3.1 KiB
C
/**
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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 "../utils/common.h"
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/* Queue class based on circular array */
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typedef struct {
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int *nums; // Array for storing queue elements
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int front; // Front pointer, pointing to the front element
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int queSize; // Tail pointer, pointing to queue end + 1
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int queCapacity; // Queue capacity
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} ArrayQueue;
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/* Constructor */
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ArrayQueue *newArrayQueue(int capacity) {
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ArrayQueue *queue = (ArrayQueue *)malloc(sizeof(ArrayQueue));
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// Initialize an array
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queue->queCapacity = capacity;
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queue->nums = (int *)malloc(sizeof(int) * queue->queCapacity);
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queue->front = queue->queSize = 0;
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return queue;
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}
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/* Destructor */
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void delArrayQueue(ArrayQueue *queue) {
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free(queue->nums);
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free(queue);
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}
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/* Get the capacity of the queue */
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int capacity(ArrayQueue *queue) {
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return queue->queCapacity;
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}
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/* Get the length of the queue */
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int size(ArrayQueue *queue) {
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return queue->queSize;
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}
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/* Determine if the queue is empty */
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bool empty(ArrayQueue *queue) {
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return queue->queSize == 0;
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}
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/* Access front element */
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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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/* Enqueue */
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void push(ArrayQueue *queue, int num) {
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if (size(queue) == capacity(queue)) {
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printf("Queue is full\r\n");
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return;
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}
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// Calculate rear pointer, pointing to rear index + 1
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// Use modulo operation to wrap the rear pointer from the end of the array back to the start
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int rear = (queue->front + queue->queSize) % queue->queCapacity;
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// Add num to the rear
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queue->nums[rear] = num;
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queue->queSize++;
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}
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/* Dequeue */
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int pop(ArrayQueue *queue) {
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int num = peek(queue);
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// Move front pointer one position backward, returning to the head of the array if it exceeds the tail
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queue->front = (queue->front + 1) % queue->queCapacity;
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queue->queSize--;
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return num;
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}
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/* Driver Code */
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int main() {
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/* Initialize queue */
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int capacity = 10;
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ArrayQueue *queue = newArrayQueue(capacity);
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/* Element enqueue */
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push(queue, 1);
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push(queue, 3);
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push(queue, 2);
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push(queue, 5);
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push(queue, 4);
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printf("Queue queue =");
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printArray(queue->nums, queue->queSize);
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/* Access front element */
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int peekNum = peek(queue);
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printf("Front element peek = %d\r\n", peekNum);
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/* Element dequeue */
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peekNum = pop(queue);
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printf("Dequeue element pop = %d, queue after dequeue = ", peekNum);
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printArray(queue->nums, queue->queSize);
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/* Get the length of the queue */
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int queueSize = size(queue);
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printf("Queue length size = %d\r\n", queueSize);
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/* Determine if the queue is empty */
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bool isEmpty = empty(queue);
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printf("Is the queue empty = %s\r\n", isEmpty ? "true" : "false");
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/* Test circular array */
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for (int i = 0; i < 10; i++) {
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push(queue, i);
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pop(queue);
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printf("After the %d round of enqueue + dequeue, queue = ", i);
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printArray(queue->nums, queue->queSize);
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}
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// Free memory
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delArrayQueue(queue);
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return 0;
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}
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