new运算符没有正确分配内存。

Question

我的代码假设使用节点数组创建单链表。

每个节点都有可变项，其中包含数据和变量，其中包含列表中下一个节点的索引。最后一个节点在其下一个数据字段中具有-1以模拟nullptr。 head保存列表中第一个节点的索引。

由于某些原因，当我尝试创建新内存时，程序会抛出bad_alloc

的实例

  

在抛出＆＃39; std :: bad_alloc＆＃39;的实例后终止调用     what（）：std :: bad_alloc

#include "ArrayList.h"
 #include <iostream>
 using namespace std;

ArrayList::ArrayList(char ch){
    array = new Node[Size];
    (array[0]).item = ch;
    (array[0]).next = 1;

    free = 1;
    head = 0;
  }

bool ArrayList::cons(char ch) {
    if (this->isFull()){
        this->doubleArray();
    }
    (array[free]).item = ch;
    (array[free]).next = head;
    head = free;
    free++;
   // cout << free << endl;
    return true;
}

bool ArrayList::isFull() const{
    int current = head;
    int count =0;
    while( (array[current]).next != -1 ){
        count++;
        current = (array[current]).next;
    }
    return (count == Size) ? true : false;
}

bool ArrayList::doubleArray() {
    int oldSize = Size;
    Size *=2;
    Node* newArray = new Node[Size]; // problem occurs here, i think

    int count =0;

    while(oldSize >= count ){
        (newArray[count]).item = (array[count]).item;
        (newArray[count]).next = (array[count]).next;
        count++;
    }
    free = count +1;
    delete [] array;
    array = newArray;
    cout <<"free: "<< free << endl;

    return true; // come up with thiss
}

void ArrayList::print() const{
    if (head == -1) return;
    int current = head;
    cout << "[ ";
    while( (array[current]).next != -1){
        cout << (array[current]).item <<" ";

        current = (array[current]).next;
    }
    cout << (array[current]).item <<"]";
    return;
}

///////////////////////////////////

#ifndef ARRAYLIST_H
#define ARRAYLIST_H
#include <iostream>
using namespace std;



class Node{
public:
    char item;
     int next;

    Node(){
        next = -1;
    }
    Node(char input){
        this->item = input;
        next = -1;
    }
};

class ArrayList{
public:
    ArrayList(char ch);
    int length() const;
    void print() const;

private:
     bool doubleArray();
    bool isFull() const;
    Node* array;
    int  Size = 5;
    int head = -1;
    int free = 0;
};
#endif

////////////////////////////////////////

#include <iostream>
#include "ArrayList.h"
using namespace std;

int main(){
    ArrayList list('1');
    list.cons('2');
    list.cons('3');
    list.cons('4');
    list.cons('5');
    list.cons('6');
    list.cons('7');
    list.print();

    //cout << list.length();
    return 0;
}