Question

我正在为一个我正在上课的项目遇到麻烦。我在递归打印spheres的链接列表方面遇到了麻烦。每当程序在特定部分运行时：

ss=ss->next;

有一个Segmentation fault: 11。问题是什么？（注意：我已经包含了必要的structs范围and sphere_list , and left out rgb and vec`，以免混乱代码。）

typedef struct sphere {
  vec *center;
  double radius;
  rgb *color;
} sphere;

typedef struct sphere_list sphere_list;
/* convention: NULL is the empty sphere list */
struct sphere_list {
  sphere *s;
  sphere_list *next;
};

void sl_print(sphere_list *ss)
{ 
if(ss==NULL)
  printf("SPHERE LIST EMPTY\n");
printf("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
printf("SPHERE LIST:\n");
int i=1;
while(ss->s!=NULL){
  printf("\t%d ", i);
  sphere_print(ss->s);
  if(ss->next==NULL){
    printf("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
    return;
    }
  ss=ss->next;
  i++;
  }
  printf("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
  return;
}

Answer 1

试试这个：

 void sl_print(sphere_list *ss)
 { 
  if(ss==NULL){
   printf("SPHERE LIST EMPTY\n");
   printf("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
   printf("SPHERE LIST:\n");
   return ;
  }
  int i=1;
  while(ss != NULL){
   printf("\t%d ", i);
   sphere_print(ss->s);
   ss=ss->next;
   i++;
  }
}

Answer 2

您在循环条件中出错了。你必须测试下一个值，因为这就是你继续使用sphere_list的原因。

void sl_print(sphere_list *ss)
{
sphere_list *tmp = ss;

if(ss==NULL)
  printf("SPHERE LIST EMPTY\n");
  printf("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
  printf("SPHERE LIST:\n");
  int i=1;
  while(tmp!=NULL){
    printf("\t%d ", i);
    if (tmp->s != NULL)
      sphere_print(tmp->s);
    if(tmp->next==NULL){
        printf("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
    return;
    }
    tmp=tmp->next;
    i++;
  }
  printf("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
  return;
}

改性*

Answer 3

struct sphere_list {
sphere *s;
sphere_list *next;
};

你为sphere *s分配了空间并使指针指向有效内存吗？我会这样做，只是一个建议。

typedef struct sphere {
vec *center;
double radius;
rgb *color;
//included the pointer in the struct//
struct sphere *next
} sphere;

此外，大多数人都不喜欢typedef结构。使代码难以阅读。

循环时链接列表的分段错误

3 个答案: