[英]Issue with dynamic memory allocation in C
I am trying to implement a sort function (counting sort, it is probably wrong): 我正在尝试实现排序功能(对排序进行计数,这可能是错误的):
void countingsortmm(int* numbers, int len, int min, int max) {
printf("Sorting %d integers with the min: %d and max: %d\n",len,min,max);
int countLen = max-min+1;
/* create an array to store counts for the occurences of a number. */
int* countingArray = (int*)malloc(countLen);
/* init all values to 0 */
for(int i = 0; i < countLen; i++) countingArray[i] = 0;
/* increment at indexes where a number occurs */
for(int i = 0; i < len; i++) countingArray[numbers[i]]++;
/* add previous indexes */
for(int i = 1; i < countLen; i++) countingArray[i] += countingArray[i-1];
/* Array where numbers will be places in a sorted order. */
int* sortedArray = (int*)malloc(len);
/* put numbers in proper place in new array and decrement */
for(int i = len-1; i >= 0; i--) sortedArray[countingArray[numbers[i]]--] = numbers[i];
/* copy contents of new sorted array to the numbers parameter. */
for(int i = 0; i < len-1; i++) numbers[i] = sortedArray[i];
free(sortedArray);
free(countingArray);
}
But I get the following error: 但是我收到以下错误:
malloc: *** error for object 0x7f8728404b88: incorrect checksum for freed object - object was probably modified after being freed.
I get a break-point at int* sortedArray = (int*)malloc(len);
我在
int* sortedArray = (int*)malloc(len);
处得到一个断点int* sortedArray = (int*)malloc(len);
. 。
I use malloc()
twice to create two different arrays within the function and I free()
them both at the end of the function when they are no longer needed. 我两次使用
malloc()
在函数内创建两个不同的数组,当不再需要它们时,我在函数的末尾将它们都free()
。 I do not explicitly modify or access their contents afterwards. 之后,我没有明确修改或访问其内容。
So what is causing this problem? 那么是什么导致了这个问题呢?
It means you're corrupting your heap. 这意味着您正在破坏堆。 Perhaps you meant
malloc(countLen * sizeof(int));
也许你的意思是
malloc(countLen * sizeof(int));
and malloc(len * sizeof(int));
和
malloc(len * sizeof(int));
? ?
malloc
takes its size in bytes. malloc
的大小以字节为单位。
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