Question

这是我在Airport.cpp的主要内容：

#include <iostream>
#include "Airport_Queue.h"
#include "Airplane.h"
#include <stdlib.h>

int main(){

    Airplane *b = new Airplane(true);
    (*b).come();
    (*b).go();
    std::cout << "........." << std::endl;
    Airport_Queue *landing_queue = new Airport_Queue(5);
    Airplane *a0 = new Airplane(true);
    (*landing_queue).enqueue(a0); //error here
    //(*landing_queue).dequeue();

return 0;

这是我的Airport_Queue.cpp

#include "Airport_Queue.h"
Airport_Queue::Airport_Queue(unsigned n){
    Airplane** a = new Airplane*[n];
    capacity = n;
    size = 0;
    head = tail = 0;
}
Airport_Queue::~Airport_Queue(){
    for (size_t i = 0; i < size; i++){
        delete a[i];
    }
    delete [] a;
}
void Airport_Queue::enqueue(Airplane* airplane){
    if (!(*this).isFull()){
        a[tail] = airplane;
        (*a[tail]).come();
        tail = (tail+1) % capacity;
        size++;
    }
    else{
        std::cerr << "Queue is full." << std::endl;
    }
}
Airplane* Airport_Queue::dequeue(){ 
    if (!(*this).isEmpty()){
        size_t x = head;
        (*a[head]).go();
        head = (head+1) % capacity;
        size--;
        return a[x];
    }
    else{
        std::cerr << "Queue is empty." << std::endl;
        return NULL;
    }   
}
bool Airport_Queue::isEmpty(){
    if (size == 0)
        return true;
    else
        return false;
}
bool Airport_Queue::isFull(){
    if (size == capacity)
        return true;
    else
        return false;
}
int Airport_Queue::getSize(){
    return size;
}

我还有一个名为Airplane的课程。我用来编译和链接的命令是 g++ -std=c+11 -Wall -g -o airport Airport.cpp Airplane.cpp Airport_Queue.cpp 如何修复此运行时错误？错误是在我拨打enqueue时。然后我得到

4 [main] airport 3796 cygwin_exception :: open_stackdumpfile：将堆栈跟踪转储到airport.exe.stackdump

请。谢谢你

Answer 1

我看到的问题：

您有一个成员变量size。您需要两个 - capacity和size。

在Airport_Queue::Airport_Queue

中

Airport_Queue::Airport_Queue(unsigned size){
    Airplane** a = new Airplane*[size];
    size = 0; // This is the argument, not the member variable.
              // The member variable remains uninitialized.
    head = tail = 0;
}

你需要：

Airport_Queue::Airport_Queue(unsigned size){
    Airplane** a = new Airplane*[size];
    this->capacity = size;
    this->size = 0;            
    head = tail = 0;
}

在Airport_Queue::~Airport_Queue

中

Airport_Queue::~Airport_Queue(){
    for (size_t i = 0; i < sizeof(a); i++){
        // sizeof(a) does not give you the number of elements
        // in the array. It just gives you the size of the pointer.
        delete a[i];
    }
    delete [] a;
}

你需要：

    Airport_Queue::~Airport_Queue(){
        for (size_t i = 0; i < this->size; i++){
            delete a[i];
        }
        delete [] a;
    }

在Airport_Queue::enqueue
中
遵循析构函数的逻辑，需要更改以下行。
```
tail = (tail+1) % sizeof(a);
```
将其更改为：
```
tail = (tail+1) % capacity;
```
In In Airport_Queue::dequeue

您的错误与上述类似。改变行
```
head = (head+1) % sizeof(a);
```
到
```
head = (head+1) % capacity;
```

在Airport_Queue::isFull

中

更改行

if (size == sizeof(a))

到

if (size == capacity)

我希望这可以解决你的大部分问题。如果有任何我错过的，希望你能找到它们。

C ++ / g ++ cygwin_exception :: open_stackdumpfile：将堆栈跟踪转储到* .exe.stackdump

1 个答案: