数据结构（C语言版）---第三章栈和队列 3.4.2 队列的链式表示和实现（循环队列）

这个是循环队列的实现，至于串及数组这两章，等有空再看，下面将学习树。

源码如下：

#include <stdio.h>
#include <stdlib.h>

#define MAXQSIZE 8

typedef int QElemType ;

typedef struct
{
    QElemType *base;
    int front;
    int rear;

}SqQueue;

int InitSqQueue(SqQueue *S)
{
    S->base = (QElemType *)malloc(sizeof(QElemType)*MAXQSIZE);

    printf("Init %p
",S->base);
    if(!S->base)
    {
        exit(0);
    }

    S->front = S->rear = 0;

    return 1;
}

int InsertQueue(SqQueue *S, QElemType e)
{
    if((S->rear + 1)%MAXQSIZE == S->front)
    {
        printf("full e:  %d  !!!
",e);

        int temp = 0;
        DeleteQueue(S,&temp);
        InsertQueue(S,e);
        return -1;
    }

    *(S->base + S->rear) = e;
    printf("insert  %p : %d
",(S->base + S->rear),e);
    
    S->rear = (S->rear + 1)%MAXQSIZE;

    return 1;
}

int DeleteQueue(SqQueue *S, QElemType * e)
{
    if(S->front == S->rear)
    {
        return -1;

    }

    *e = *(S->base + S->front);
    printf("del  %p : %d
",(S->base + S->front),*e);
    S->front = (S->front + 1)%MAXQSIZE;

    return 1;
}


void PrintQueue(SqQueue *S)
{
    int *a = S->base;

    int front = S->front;
    int rear = S->rear;
    
    while(front != rear)
    {
        printf("%d	",a[front]);
        front ++;
    }

    printf("
");

}

void DestoryQueue(SqQueue *S)
{
    free(S->base);
}

int main(int argc ,char** argv)
{
    SqQueue S;
    printf("main  %p
",S.base);
    InitSqQueue(&S);

    int i = 0;
    for(i = 0 ; i < 20 ; i++)
    {
        InsertQueue(&S,i);
    }

//    PrintQueue(&S);

    DeleteQueue(&S,&i);

//    PrintQueue(&S);

    printf("main  %p
",S.base);
    free(S.base);
    printf("main  %p
",S.base);
    
    //S.base = NULL;
//    DestoryQueue(&S);
    return 1;
}

运行结果如下：

root@ubuntu:/mnt/hgfs/E/Lessons/MyExercise/DS/3# ./SqQueue                
main  0xe344d5
Init 0x822d008
insert  0x822d008 : 0
insert  0x822d00c : 1
insert  0x822d010 : 2
insert  0x822d014 : 3
insert  0x822d018 : 4
insert  0x822d01c : 5
insert  0x822d020 : 6
full e:  7  !!!
del  0x822d008 : 0
insert  0x822d024 : 7
full e:  8  !!!
del  0x822d00c : 1
insert  0x822d008 : 8
full e:  9  !!!
del  0x822d010 : 2
insert  0x822d00c : 9
full e:  10  !!!
del  0x822d014 : 3
insert  0x822d010 : 10
full e:  11  !!!
del  0x822d018 : 4
insert  0x822d014 : 11
full e:  12  !!!
del  0x822d01c : 5
insert  0x822d018 : 12
full e:  13  !!!
del  0x822d020 : 6
insert  0x822d01c : 13
full e:  14  !!!
del  0x822d024 : 7
insert  0x822d020 : 14
full e:  15  !!!
del  0x822d008 : 8
insert  0x822d024 : 15
full e:  16  !!!
del  0x822d00c : 9
insert  0x822d008 : 16
full e:  17  !!!
del  0x822d010 : 10
insert  0x822d00c : 17
full e:  18  !!!
del  0x822d014 : 11
insert  0x822d010 : 18
full e:  19  !!!
del  0x822d018 : 12
insert  0x822d014 : 19
del  0x822d01c : 13
main  0x822d008
main  0x822d008
root@ubuntu:/mnt/hgfs/E/Lessons/MyExercise/DS/3#