[英]“Program received signal SIGSEGV, Segmentation fault.” error message from gdb debugger
Something in the while loop is giving me this error. while 循环中的某些东西给了我这个错误。 I can't figure out what to look up because this error seems way to common to find out what to do with my specific example
我不知道要查找什么,因为这个错误似乎很常见,可以找出如何处理我的具体示例
#include <stdlib.h>
#include <stdio.h>
/*Structure declarations*/
struct Data {
int id_number;
float ratings;
};
typedef struct Node{
struct Data player;
struct Node *next;
}Node;
/*function declaration*/
void push(struct Node *list_head, int unique_id, float grade);
int main(){
/* Initialize list_head to Null since list is empty at first */
Node *list_head = NULL;
Node *traversalPtr;
push(list_head, 1, 4.0);
push(list_head, 2, 3.87);
push(list_head, 3, 3.60);
traversalPtr = list_head;
while(traversalPtr -> next != NULL){
printf("%d\n",traversalPtr -> player.id_number);
traversalPtr = traversalPtr -> next;
}
}
...function declarations
The problem is that the function问题是 function
void push(struct Node *list_head, int unique_id, float grade);
deals with copies of original pointers defined in main because the pointers are passed by values.处理 main 中定义的原始指针的副本,因为指针是按值传递的。
You should declare the function like您应该像这样声明 function
void push(struct Node **list_head, int unique_id, float grade);
and call it like并称它为
push( &list_head, 1, 4.0 );
Here is an example of how the function can be defined (I assume that the function appends nodes to its tail).下面是如何定义 function 的示例(我假设 function 将节点附加到其尾部)。
int push(struct Node **list_head, int unique_id, float grade)
{
struct Node *node = malloc( sizeof( struct Node ) );
int success = node != NULL;
if ( success )
{
node->player.id_number = unique_id;
node->player.ratings = grade;
node->next = NULL;
while ( *list_head ) list_head = &( *list_head )->next;
*list_head = node;
}
return success;
}
Also this loop还有这个循环
traversalPtr = list_head;
while(traversalPtr -> next != NULL){
printf("%d\n",traversalPtr -> player.id_number);
traversalPtr = traversalPtr -> next;
}
is incorrect.是不正确的。 It should look like
它应该看起来像
traversalPtr = list_head;
while(traversalPtr != NULL){
printf("%d\n",traversalPtr -> player.id_number);
traversalPtr = traversalPtr -> next;
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.