mirror of https://github.com/TheAlgorithms/C
105 lines
2.7 KiB
C
105 lines
2.7 KiB
C
// Queue ADT implementation ... COMP2521
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#include "queue.h"
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#include <assert.h>
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#include <stdlib.h>
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typedef struct node
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{
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int data;
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struct node *next;
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} NodeT;
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typedef struct QueueRep
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{
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int length;
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NodeT *head;
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NodeT *tail;
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} QueueRep;
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// set up empty queue
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queue newQueue()
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{
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queue Q = malloc(sizeof(QueueRep));
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Q->length = 0;
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Q->head = NULL;
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Q->tail = NULL;
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return Q;
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}
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// remove unwanted queue
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void dropQueue(queue Q)
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{
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NodeT *curr = Q->head;
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while (curr != NULL)
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{
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NodeT *temp = curr->next;
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free(curr);
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curr = temp;
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}
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free(Q);
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}
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// check whether queue is empty
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int QueueIsEmpty(queue Q) { return (Q->length == 0); }
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// insert an int at end of queue
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void QueueEnqueue(queue Q, int v)
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{
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NodeT *new = malloc(sizeof(NodeT));
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assert(new != NULL);
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new->data = v;
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new->next = NULL;
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if (Q->tail != NULL)
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{
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Q->tail->next = new;
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Q->tail = new;
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}
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else
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{
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Q->head = new;
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Q->tail = new;
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}
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Q->length++;
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}
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// remove int from front of queue
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int QueueDequeue(queue Q)
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{
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assert(Q->length > 0);
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NodeT *p = Q->head;
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Q->head = Q->head->next;
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if (Q->head == NULL)
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{
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Q->tail = NULL;
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}
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Q->length--;
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int d = p->data;
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free(p);
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return d;
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}
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// By
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// .----------------. .----------------. .----------------.
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// .-----------------. .----------------. .----------------.
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// | .--------------. || .--------------. || .--------------. ||
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// .--------------. | | .--------------. || .--------------. | | | _________ |
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// || | _____ _____ | || | __ | || | ____ _____ | | | | ____ ____
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// | || | ____ | | | | | _ _ | | || ||_ _||_ _|| || | / \
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// | || ||_ \|_ _| | | | | |_ || _| | || | .' `. | | | | |_/ | |
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// \_| | || | | | | | | || | / /\ \ | || | | \ | | | | | | |
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// |__| | | || | / .--. \ | | | | | | | || | | ' ' | | || |
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// / ____ \ | || | | |\ \| | | | | | | __ | | || | | | | | | |
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// | | _| |_ | || | \ `--' / | || | _/ / \ \_ | || | _| |_\ |_
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// | | | | _| | | |_ | || | \ `--' / | | | | |_____| | || | `.__.'
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// | || ||____| |____|| || ||_____|\____| | | | | |____||____| | || | `.____.'
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// | | | | | || | | || | | || | | | | |
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// | || | | | | '--------------' || '--------------' ||
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// '--------------' || '--------------' | | '--------------' || '--------------'
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// |
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// '----------------' '----------------' '----------------'
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// '----------------' '----------------' '----------------'
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// Email : z5261243@unsw.edu.au
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// hhoanhtuann@gmail.com
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