linked list question

[sumdude]

First off let me say this is not Hw im trying to remember how linked lists work etc for my upcoming fall class: However what im trying to do is traverse a linear linked list thats sorted and when i find the node im looking for to delete it. Its been a while since ive messed with data structures so im trying to refresh myself. Please see the code i have below and tell me why only 6,5,4,3,2,1 prints out. If you could correct it in code I would greatly appreciate it.

#include<stdlib.h>
#include<stdio.h>

struct list_el {
int val;
struct list_el * next;
};

typedef struct list_el item;

int main() {
item * curr, * head, * temp;
int i;

head = NULL;

for(i=1;i<=10;i++) {
curr = malloc(sizeof(item));
curr->val = i;
curr->next = head;
head = curr;
}

curr = head;
int zz,number=10;

for(zz=1;zz<=10;zz++)
{


if(curr->val==5)
{ 
                
  temp->next = curr->next;
//printf("You have found the number 5 so im gonna delete it\n");

}


else if(curr->val!=5)
{
     
printf("current possition = %d\n", number);
number--;

temp = curr;
curr = curr->next;
}


}

curr=temp;


while(curr) {
printf("%d\n", curr->val);
curr = curr->next ;
}

system("PAUSE");
return 0;
}

[roaan]

Does your code compile ????????????? It does not.

[sumdude]

yes it compiles.

i just re-copied it

#include<stdlib.h>
#include<stdio.h>

struct list_el {
int val;
struct list_el * next;
};

typedef struct list_el item;

int main() {
item * curr, * head, * temp;
int i;

head = NULL;

for(i=1;i<=10;i++) {
curr = malloc(sizeof(item));
curr->val = i;
curr->next = head;
head = curr;
}

curr = head;
int zz,number=10;

for(zz=1;zz<=10;zz++)
{


if(curr->val==5)
{ 
                head->next = temp;
  temp->next = curr->next;
//printf("You have found the number 5 so im gonna delete it\n");

}


else if(curr->val!=5)
{
     
printf("current possition = %d\n", number);
number--;

temp = curr;
curr = curr->next;
}


}

curr=temp;


while(curr) {
printf("%d\n", curr->val);
curr = curr->next ;
}

system("PAUSE");
return 0;
}

[LPHard]

you can print out this code

for(i=1;i<=10;i++) {
curr = malloc(sizeof(item));
curr->val = i;
curr->next = head;
head = curr;
}

u got wrong , u reverse the list !

[LPHard]

this code is ok
try it...

#include<stdlib.h>
#include<stdio.h>

struct list_el {
int val;
struct list_el * next;
};

typedef struct list_el item;

int main() {
item * curr, * head, * temp;
int i;

head = NULL;

for(i=1;i<=10 ;i++) {
    
curr = malloc(sizeof(item));

// this is sure for newest Node
curr->val = i;
curr->next = NULL;

if(i==1){
head = curr; // head only sets 1 time
temp = curr;
}

// moving...

temp->next = curr;
temp = curr;

 

}



while(head) {
    printf("%d\n", head->val);
    head = head->next ;
}




    system("PAUSE");
    return 0;
}

[Dino]

My version. It's easier for me to think forward than backwards, so I redid it a bit.

#include<stdlib.h>
#include<stdio.h>

struct list_el {
	int val;
	struct list_el * next;
};

typedef struct list_el item;

int main() {
	item * curr, * head, * prev ;
	int i;
	int to_delete = 5 ; 

	head = NULL;
	curr = NULL ; 
	prev = NULL ; 
	
	for ( i=0 ; i<10 ; i++) {
		prev = curr ; 
		curr = malloc(sizeof(item));
		curr->val  = i;
		curr->next = 0 ; 
		if (i==0) head = curr ;  		
		else prev->next = curr ; 
	}
	
	curr = head ; // reset to top of linked list 
	prev = NULL ; 
	while (curr) {
		if (curr->val == to_delete) { 
			if (prev) prev->next = curr->next ; // fix forward chain 
			else head = curr->next ;
			free(curr) ; 
			curr = NULL ; 
		}
		else { 
			prev = curr ; 
			curr = curr->next ; 
		}
	}
		
	/*	ignore this - just an exercise in obfuscation.... 
	while (curr) {
		curr->val == to_delete ? ( { prev != NULL ? (prev->next = curr->next) : 
		( head = curr->next ); 	free(curr) ; curr = NULL ; } ) : 
		( { prev = curr ; curr = curr->next ; }) ;
	}
	*/ 	

	curr = head ;  // reset to top of list again 
	while(curr) {
		printf("%d\n", curr->val);
		curr = curr->next ;
	}
	return 0;
}