C. Linked lists. Inserting an element before another - c

Question

Right now I have a program (shown below) that inserts an element (E) after (F). For example if we input n = 4 and then insert 4 elements 2 3 3 4, followed by our 'F' value which is 3 and E value which is 6, the program will edit the list inserting E (6) after F (3), resulting in a list edition from 2 3 3 4 into 2 3 6 3 4
I am looking for a way to insert a value 'E' BEFORE an F, not after. Could anyone explain what changes may be required to this code to achieve the same?
#include <stdio.h>
#include <stdlib.h>
struct sarasas { int duomuo; struct sarasas *next, *prev; };
typedef struct sarasas Sarasas;
typedef Sarasas *SarasasPtr;
int main()
{
int d,i,n,j,e,f;
SarasasPtr Sar,x,temp,prev=NULL;
SarasasPtr head= NULL;
printf("Insert 'n' \n");
scanf("%d",&n);
for (i=0; i<n; i++) {
printf("Insert an element: \n");
scanf("%d",&d);
x=(SarasasPtr) malloc(sizeof( Sarasas ));
x->duomuo = d;
x->next = NULL;
if(head == NULL) {
head = x;
} else {
temp = head;
while(temp!=NULL) {
prev = temp;
temp = temp->next;
}
prev->next = x;
}
}
printf("Insert an element after which one you want another element to be inserted\n");
scanf("%d",&e);
printf("Insert element which you want to insert\n");
scanf("%d",&f);
temp = head;
int pakeista = 0;
while(temp!=NULL) {
//printf("%d",temp->duomuo);
if (temp->duomuo == e) {
if (changed == 0) {
x=(SarasasPtr) malloc(sizeof( Sarasas ));
x->duomuo=f;
x->next=temp->next;
temp->next=x;
n++;
changed = 1;
}
}
temp=temp->next;
}
Sar = head;
for (i=0; i<n; i++) {
printf("Sk Nr. %i: %d\n",i+1,Sar->duomuo);
Sar = Sar->next;
}
}

Answer 1

You simply need to check temp->next->duomuo instead of temp->duomuo
while(temp->next!=NULL) {
if (temp->next->duomuo == e) {
if (changed == 0) {
x=(SarasasPtr) malloc(sizeof( Sarasas ));
x->duomuo=f;
x->next=temp->next;
temp->next=x;
n++;
changed = 1;
}
}
temp=temp->next;
}
I would also suggest that instead of this changed thing that you are doing, just break from the loop after you replace. This way your loop won't run more times than it needs to.
while(temp->next!=NULL) {
if (temp->next->duomuo == e) {
x=(SarasasPtr) malloc(sizeof( Sarasas ));
x->duomuo=f;
x->next=temp->next;
temp->next=x;
n++;
break;
}
temp=temp->next;
}