C - realloc():两次计算后下一个大小无效

Question

我创建了存储数字数组的结构。数组是动态分配的。尝试重新分配函数中的某些空间时出现问题。错误是

realloc(): invalid next size
Aborted (core dumped)

结构如下

typedef struct big_number {
    unsigned int *digits;
    int num_of_digits;
}BigNumber;

该函数如下所示(将数字与 BigNumber 相乘(：

void scale(BigNumber a, int c, BigNumber* scaled)
{
    scaled->num_of_digits = a.num_of_digits;
    scaled->digits = NULL;
    scaled->digits = malloc(scaled->num_of_digits * sizeof (unsigned int));
    if (scaled->digits == NULL) {
        error();
    }
    int carry = 0;
    for (int i = scaled->num_of_digits; i >= 0; i--) {
        int tmp = a.digits[i] * c + carry;
        scaled->digits[i] = tmp % 10;
        carry = tmp / 10;
    }
    if (carry != 0) {
        //While trying realloc in this line problem occurs
        scaled->num_of_digits += 1;
        scaled->digits = realloc(scaled->digits, scaled->num_of_digits * sizeof (unsigned int));
        scaled->digits[0] = carry;
    }
}

主调用如下所示：

    printf("Results:n");
    scale(num_b, 5, &pomocna);
    print_big_number(pomocna);
    free(pomocna.digits);

Answer 1

数组从0到n-1。您正在写信

给不存在array[n]

scaled->digits = malloc(scaled->num_of_digits * sizeof (unsigned int));
for (int i = scaled->num_of_digits; i >= 0; i--) { // AAA
        int tmp = a.digits[i] * c + carry;
        scaled->digits[i] = tmp % 10;             // BBB

在行 AAA 中，您将i设置为数组的大小(n

(

在行BBB你尝试改变scaled->digits[i] (array[n] (