删除数组时堆损坏错误

Question

我试图读取包含随机数列表的文本文件,并使用mergesort进行排序.数字被读入动态数组.不幸的是,每当我尝试删除未使用的数组时,都会检测到堆损坏错误.

Mergesort功能:

void mergesort(int *arr, int first, int last)
{
if(first < last)
   {
   int middle = ((first + last)/2);
   mergesort(arr, first, middle);
   mergesort(arr, middle+1, last);
   merge(arr, first, last); 
   }
}

删除tempArr时合并函数出错:

void merge(int *arr, int first, int last)
{
int *tempArr = new int[last];

int mid = (first+last)/2;
int first1 = first;
int last1 = mid;
int first2 = mid + 1;
int last2 = last;

int index = first1;

for(; (first1 <= last1) && (first2 <= last2); ++index)
{
    if (arr[first1] < arr[first2])
    {
        tempArr[index] = arr[first1];
        ++first1;
    }
    else
    {
        tempArr[index] = arr[first2];
        ++first2;
    }
}

for(; first1 <= last1; ++first1, ++index)
    tempArr[index] = arr[first1];

for(; first2 <= last2; ++first2, ++index)
    tempArr[index] = arr[first2];

for(index=first;index<=last;++index)
    arr[index] = tempArr[index];

delete [] tempArr;
}

Answer 1

问题似乎是你将数组分配为int *tempArr = new int[last].它的元素的数量last和它们的指数0,1...... last - 1.

接近函数的末尾,你有这个:

for(; first2 <= last2; ++first2, ++index)
    tempArr[index] = arr[first2];

last2初始化为的值last.这意味着循环中的最终赋值将是何时index == last,因此您正在访问tempArr[last].这超出了数组范围.