循环队列（严3.30）--------西工大NOJ习题.9

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
typedef struct _Queue
{
    int max_size;
    int rear;
    int lenth;
    int* data;
}Queue;
Queue* Create(int n)
{
    Queue* Q = (Queue*)malloc(sizeof(Queue));
    Q->data = (int*)calloc(n, sizeof(int));
    Q->lenth = 0;
    Q->max_size = n;
    Q->rear = 0;//注意：当循环队列内部元素个数为0时，rear无意义。
    return Q;
}
int Push(Queue* Q, int e)
{
    if (Q->lenth == 0)
    {
        Q->rear = 0;
        Q->lenth = 1;
        Q->data[0] = e;
        return 1;
    }
    if (Q->lenth >= Q->max_size)
    {
        return 0;
    }
    Q->rear = (Q->rear + 1) % Q->max_size;
    Q->data[Q->rear] = e;
    Q->lenth++;
    return 1;

}
int Get_head(Queue* Q)
{
    int t = Q->rear - Q->lenth + 1;
    if (t < 0)
    {
        t = Q->max_size + t;
    }
    return Q->data[t];
}
int Full(Queue* Q)
{
    if (Q->lenth >= Q->max_size)
        return 1;
    else
        return 0;
}
int Empty(Queue* Q)
{
    if (Q->lenth == 0)
        return 1;
    else
        return 0;
}
void Print(Queue* Q)
{
    int t = Q->rear - Q->lenth + 1;
    if (t < 0)
    {
        t = Q->max_size + t;
    }
    for (int i = 0; i < Q->lenth; i++)
    {
        printf("%d ", Q->data[t]);
        t = (t + 1) % Q->max_size;
    }
}
void Read(Queue* Q)
{
    char buf[12];
    while (1)
    {
        scanf("%s", buf);
        if (buf[0] == 'n')
            return;
        if (buf[0] == 'y')
            return;
        Push(Q, atoi(buf));
    }
}
void Delete(Queue* Q, int e)
{
    int t = Q->rear - Q->lenth + 1;
    if (t < 0)
    {
        t = Q->max_size + t;
    }
    while (Q->data[t] != e)
    {
        Q->lenth -= 1;
        t = (t + 1) % Q->max_size;
    }
    if (Get_head(Q) == e)
        Q->lenth -= 1;
}
int main()
{
    int n;
    scanf("%d", &n);
    Queue* Q = Create(n);
    Read(Q);
    int elem;
    scanf("%d", &elem);
    Delete(Q,elem);
    Print(Q);
    putchar('\n');
    printf("%d", Get_head(Q));
    return 0;
}