Question

我想增加编码为双指针的矩阵的高度，但每次尝试时，我的代码都会出现段错误。我尝试了这个，但它不起作用：

void get_matrix_bigger(int ** matrix, int height, int width)
{
   int new_width, new_height, i;
   scanf("%d%d", &new_height, &new_width);

   matrix = realloc(matrix, new_height * sizeof(int *));
   for(i = height; i < new_height; i++)
       matrix[i] = malloc(new_width * sizeof(int));

}

int main(void)
{
   int ** matrix, height, width;
   scanf("%d%d", &height, &width);

   matrix = malloc(height * sizeof(int *));

   for(i = 0; i < height; i++)
       matrix[i] = malloc(width * sizeof(int));

   get_matrix_bigger(matrix, height, width);

   return 0;
}

Answer 1

在get_matrix_bigger函数中你应该传递***矩阵，否则你从get_matrix_bigger出来后你仍然在堆栈上有旧指针。

void get_matrix_bigger(int *** matrix, int height, int width)
{
   int new_width, new_height, i;
   scanf("%d%d", &new_height, &new_width);

   *matrix = realloc(*matrix, new_height * sizeof(int *));
   for(i = height; i < new_height; i++)
       *matrix[i] = malloc(new_width * sizeof(int));

}

并在main中使用它：

get_matrix_bigger(&matrix, height, width);

动态调整矩阵大小会导致分段错误

1 个答案: