为什么这个静态队列程序不起作用？ 它突然以自己的方式结束

Question

bool queueIsFull(int rearPointer)
{
    if(rearPointer==9)
        return 1;
    else
        return 0;
}

void PUSH (int queue[], int value, int *frontPointer, int *rearPointer)
{
    *rearPointer++;
    if(*frontPointer==-1)
        *frontPointer=0;
    queue[*rearPointer] = value;
}

bool queueIsEmpty (int frontPointer, int rearPointer)
{
    if(rearPointer==(-1) && frontPointer==(-1))
        return true;
    else
        return false;
}

void POP (int* frontPointer, int* rearPointer, int queue[])
{
    cout << "\n Deleted element is: " << queue[*frontPointer];
    if(*rearPointer==*frontPointer)
    {
        *rearPointer=-1;
        *frontPointer=-1;
    }
    else
        *frontPointer++;
}


int main()
{
    int option, value, queue[10];
    int  rearPointer=-1, frontPointer=-1;
    while(1)
    {
        cout << "\n----------[STATIC QUEUE]--------\nEnter a choice: \n1. PUSH AN ELEMENT\n2. POP AN ELEMENT\n3. EXIT\n";
        cin >> option;
        switch(option)
        {
            case 1: if(!queueIsFull(rearPointer))
                    {
                        cout << "\nEnter a value to push in queue: ";
                        cin >> value;
                        PUSH(queue, value, &frontPointer, &rearPointer);
                    }
                    else
                        cout << "\nqueue is full. Empty the queue elements and try again!";
                    break;

            case 2: if(!queueIsEmpty(frontPointer, rearPointer)) // either of the parameters would do.
                        POP(&frontPointer, &rearPointer, queue); // queue is optional. You only need it to display thte poped value.
                    else
                        cout << "\nqueue is already empty. Enter some elements";
                    break;

            case 3: return 0;
                    break;

            default: cout << "\nWrong choice! Try again.";
                   break;
        }
    }
}

I can't get anywhere and I'm not able to debug the problem because the program gets terminated abruptly when I enter values in the queue! That's why it is getting difficult to understand where the root problem is! Why is it happening?

Also, can you give me some tips on how to solve such problems in the future?

Answer 1

The PUSH function is actually incrementing the pointer rearPointer instead of the value it points to.

Change

*rearPointer++;

to

(*rearPointer)++;

Answer 2

To resolve this and other similar issue, you can run the app under debugger, I think the debugger will catch the exception and you can get some clue about what's wrong.

If you are using IDE, you can find the menu item with similar text as "run with debugger", or you can first run the app, and attach the debugger. You can add sleep for delay to make sure you have time to attach debugger.