Basic cyclic queue operations

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/** Basic cyclic queue operations. * Use less than one element space. It is agreed that "the queue header pointer is at the next position of the queue's tail Pointer" will be used as a sign of the queue's full capacity. * "The queue header pointer is equal to the end pointer of the queue" as a flag of queue null. */# Include <stdio. h> # include <stdbool. h> # include <malloc. h> # define maxqsize 100 typedef char elemtype; typedef struct {elemtype * base; int front; int rear;} queue; bool initqueue (queue * Queue ); int queuelength (queue Queue); bool enqueue (queue * queue, elemtype E); bool dequeue (queue * queue, elemtype * E); int main () {queue; elemtype ELEM [26], temp; int I, length; initqueue (& Queue); for (I = 0; I <26; I ++) {ele M [I] = 'A' + I; enqueue (& queue, ELEM [I]);} length = queuelength (Queue); printf ("length: % d \ n ", length); for (I = 0; I <length; I ++) {dequeue (& queue, & temp); putchar (temp );} return 0;} // construct an empty queue. Bool initqueue (queue * Queue) {queue-> base = (elemtype *) malloc (sizeof (elemtype) * maxqsize); If (! Queue-> base) return false; queue-> front = queue-> rear = 0; return true;} // evaluate the queue length. Int queuelength (queue Queue) {return (queue. Rear-queue. Front + maxqsize) % maxqsize;} // insert element e to the end of the queue. Bool enqueue (queue * queue, elemtype e) {If (queue-> rear + 1) % maxqsize = queue-> front) // return false when the queue is full; queue-> base [queue-> rear] = E; queue-> rear = (queue-> rear + 1) % maxqsize; return true ;} // Delete the queue Header element and use e to return its value. Bool dequeue (queue * queue, elemtype * E) {If (queue-> front = queue-> rear) // return false for empty queue; * E = queue-> base [queue-> front]; queue-> front = (queue-> front + 1) % maxqsize; return true ;}