Linked List of Ordered Linked Lists - c

Question

I am trying to create an (ordered) linked list of (ordered) linked lists. The list-of-list links are carried by the first nodes of its member lists. I am trying to achieve this via the following code, but my program crashes right after I try to view the second node into the list of lists.
Here's a schematic of the data structure I am trying to construct:
Code:
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
struct node{
int number;
struct node*next;
struct node*lsnext;
};
typedef struct node Node;
Node* insertValue(Node * list, int value);
void display(Node*);
Node* insertArr(Node * list, int value);
int main()
{
Node *globalList = NULL, *lists,*start,*save;
int nbrOfLists, listNo, nbrOfVal, valNo, val;
printf("\n Enter the number of lists:");
scanf("%d", &nbrOfLists);
if(nbrOfLists < 0)
return -1;
for(listNo = 0; listNo < nbrOfLists; listNo++)
{
printf("\n\n Enter the number of inputs to the list %d: \n ",listNo+1);
scanf("%d", &nbrOfVal);
lists = NULL;
for(valNo = 0; valNo < nbrOfVal; valNo++)
{
printf("Enter node value %d:", valNo+1);
scanf("%d", &val);
// Here we insert the value in both lists
lists= insertValue(lists, val);
globalList = insertValue(globalList, val);
}
start=lists;
if(listNo==0){
save=start;
}
start=start->lsnext;
printf("\n The list %d is: ",listNo+1);
display(lists);
}
printf("\n\n The final list is: ");
display(globalList);
printf("The first list is");
display(save);
printf("The second list is");
display(save->lsnext); // CRASHES HERE
return 0;
}
Node* insertValue(Node * list, int value)
{
Node *newNode, *m;
newNode = malloc(sizeof(Node));
newNode->number=value;
if(list == NULL)
{
newNode->next=NULL;
return newNode;
}
if(value < list->number)
{
newNode->next = list;
return newNode;
}
m = list;
while(m->next)
{
if(value < m->next->number)
break;
m = m->next;
}
newNode->next = m->next;
m->next = newNode;
return list;
}
void display(Node*nodex){
while(nodex)
{
printf("%d ->",nodex->number);
nodex=nodex->next;
}
}

Answer 1

The problem is you never assign the lsnext node pointer. You will want to make sure you set this pointer equal to "lists" prior to resetting your start pointer. And you shouldn't need the following line of code:
start=start->lsnext;
That fixes your crashing issue that you mention, however the source code has other errors. Running your application through GDB will be invaluable in ensuring your pointer values are what you think they should be at each step, as well as a source code formatter to ensure readability, making it easier to tell which code belongs inside which blocks.