malloc无法分配内存

Question

为什么malloc无法正常分配内存

#include <stdio.h>
#include <stdlib.h>
#define OK 1
#define ERROR 0
#define INFEASIBLE -1
#define OVERFLOW -2
typedef int Status;
typedef int QElemType;
typedef struct
{
    QElemType *base;
    int front;
    int rear;
}SqQueue;

Status InitQueue(SqQueue *Q,int n)
{
    Q->base= (QElemType *)malloc(n*sizeof(QElemType));
    if(!Q->base) exit(OVERFLOW);
    Q->front=Q->rear=0;
    return OK;
}

//int QueueLength(SqQueue *Q)
//{
//    return (Q->rear-Q->front+MAXSIZE)%MAXSIZE;
//}

Status EnQueue(SqQueue *Q,QElemType e,int n)
{
    if((Q->rear+1)%n==Q->front) return ERROR;
    Q->base[Q->rear]=e;
    Q->rear=(Q->rear+1)%n;
    return OK;
}
// Status Queue(SqQueue *Q){
//     while
// }
void DeQueue(SqQueue *Q,QElemType *e,int n)
{
    while(Q->base[Q->front]=0){
        Q->front=(Q->front+1)%n;
    }
    *e=Q->base[Q->front];
    Q->front=(Q->front+1)%n;
}

//Status GetHead(SqQueue *Q,QElemType *e)
//{
//    if(Q->rear==Q->front) return ERROR;
//    *e=Q->base[Q->front];
//    return OK;
//}

void DestroyQueue(SqQueue *Q)
{
    if(Q->base) free(Q->base);
    Q->base=NULL;
    Q->front=0;
    Q->rear=0;
}

int main()
{
    SqQueue *Q;
    //自行编写代码
    int n;
    scanf("%d",&n);
    int m;
    scanf("%d",&m);
    InitQueue(Q,n);
    printf("+");
    for (int i=1;i<=n;i++){
        EnQueue(Q,i,n);
    }
    int e;
    int k=n;
    while(k!=1){
        int f;
        for(int j=0;j<m;j++){
            DeQueue(Q,&f,n);
        }
        Q->base[Q->front]=0;
        k--;
    }
    DeQueue(Q,&e,n);
    printf("%d",e);
    return 0;
}

Answer 1

两个问题

• 判断相等写成了单个=
• 初始化方式错了

这里判断相等写错了

main函数中初始化方式错了

对应的访问方式也需要更改，->用于结构体指针，.用于结构体变量
所有函数里面的Q都需要改成&Q

修改完毕后，代码可以运行了，但是有没有逻辑错误我不知道

如果对你有帮助，还请点个采纳，万分感谢！

#include <stdio.h>
#include <stdlib.h>
#define OK 1
#define ERROR 0
#define INFEASIBLE -1
#define OVERFLOW -2
typedef int Status;
typedef int QElemType;
typedef struct SqQueue
{
    QElemType* base;
    int front;
    int rear;
}SqQueue;

Status InitQueue(SqQueue* Q, int n)
{
    Q->base = (QElemType*)malloc(n * sizeof(QElemType));
    if (!Q->base) exit(OVERFLOW);
    Q->front = Q->rear = 0;
    return OK;
}

//int QueueLength(SqQueue *Q)
//{
//    return (Q->rear-Q->front+MAXSIZE)%MAXSIZE;
//}

Status EnQueue(SqQueue* Q, QElemType e, int n)
{
    if ((Q->rear + 1) % n == Q->front) return ERROR;
    Q->base[Q->rear] = e;
    Q->rear = (Q->rear + 1) % n;
    return OK;
}
// Status Queue(SqQueue *Q){
//     while
// }
void DeQueue(SqQueue* Q, QElemType* e, int n)
{
    while (Q->base[Q->front] == 0) {
        Q->front = (Q->front + 1) % n;
    }
    *e = Q->base[Q->front];
    Q->front = (Q->front + 1) % n;
}

//Status GetHead(SqQueue *Q,QElemType *e)
//{
//    if(Q->rear==Q->front) return ERROR;
//    *e=Q->base[Q->front];
//    return OK;
//}

void DestroyQueue(SqQueue* Q)
{
    if (Q->base) free(Q->base);
    Q->base = NULL;
    Q->front = 0;
    Q->rear = 0;
}

int main()
{
    SqQueue Q;
    //自行编写代码
    int n;
    scanf("%d", &n);
    int m;
    scanf("%d", &m);
    InitQueue(&Q, n);
    printf("+");
    for (int i = 1; i <= n; i++) {
        EnQueue(&Q, i, n);
    }
    int e;
    int k = n;
    while (k != 1) {
        int f;
        for (int j = 0; j < m; j++) {
            DeQueue(&Q, &f, n);
        }
        Q.base[Q.front] = 0;
        k--;
    }
    DeQueue(&Q, &e, n);
    printf("%d", e);
    return 0;
}