Linked lists in C with chars and integers (troubleshooting) - c

Question

I want to programm a linked list in C, trying to apply everything I've learned so far.
I wrote this program to create a linked list:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct node *head = NULL;
//Define struct node
struct node{
char * name;
int num;
struct node * next;
};
//Print List
void printList(){
struct node * temp = head;
while (temp != NULL){
printf("%s", temp->name);
printf("%d", temp->num);
temp = temp->next;
}
}
//Create New Node
struct node * newNode (char * name, int num){
struct node * newNode = (struct node*)malloc(sizeof(struct node));
newNode->name = name;
newNode->num = num;
newNode->next = NULL;
return newNode;
}
//Function to insert and sort Elements
void insertSorted (char * name, int num){
//Empty Liste -> Head is NULL
if (head == NULL){
head = newNode(name, num);
}
else if (strcmp(name, head->name) <=0){
// strcmp-output = -1 ->string 1 > string 2; 0 -> both strings are the same
struct node * temp = newNode(name, num);
temp->next = head;
head = temp;}
struct node * current = head; struct node *prev = NULL;
if (strcmp(name, current->name)>0){ //-> 1, string1 < string 2 ->insert after
while(current != NULL && strcmp(name, current->name)<=0){
prev = current;
current = current->next;
}
struct node * temp = newNode(name, num);
prev->next = temp;
temp->next = current;
}
}
//Test of the linked list
int main()
{
char name; int num;
//Testprogram
printf("Enter a name\n");
scanf("%s", &name);
printf("Enter a number\n");
scanf("%d", &num);
insertSorted(&name, num);
char name2; int num2;
printf("Enter a name\n");
scanf("%s", &name);
printf("Enter a number\n");
scanf("%d", &num2);
insertSorted(&name2, num2);*/
char name3; int num3;
printf("Enter a name\n");
scanf("%s", &name);
printf("Enter a number\n");
scanf("%d", &num3);
insertSorted(&name3, num3);
printList();
return 0;
}
Output example:
Input: Anna 1, Claudio 2, Berta 3
Output: 32Berta1
It somehow...makes the Names vanish and the numbers are in the wrong order too. I'm pretty new to programming, so I have troubles fixing this by myself.
Any help would be hugely appreciated :) Not only to fix the error, but also tips on how to program more...elegantly, so to say.
Thanks :)
//Edit:
Thank you for all the input so far! I messed up the input of the string while testing the program.
As suggested I tried to skip the part with the input, testing the linked list like this in main() (thanks Julien!):
insertSorted("Anna", 1);
insertSorted("Claudio", 2);
insertSorted("Berta", 3);
printList();
it results in the programm not executing and exiting with a negative number error code. Does this point to an infinite loop?

Answer 1

I haven't looked at the linked list details, but one issue I see is that you are using single char variable to store the names (which should be an array or characters). This lack of enough space to store the input make you program have an undefined behaviour after the call to scanf.
As #franji1 stated, try working step by step. If you want to check the code of your list, try testing:
insertSorted("Anna", 1);
insertSorted("Claudio", 2);
insertSorted("Berta", 3);
And check the result is what you expect. Once this is working, add the code asking for input from the user using scanf.

Answer 2

Im not an expert at C but since you mentioned code elegancy I can tell you this. You didn't need to use all these different if statements, you could use the while loop from the begining and insert after you find a name that is bigger than current. This will work even if it has to be inserted before the head node as long as you check that prev is not null. I hope I helped you and that you will find a solution to your problem!